@article {43217, title = {First synthesis of a noreremophilane isolated from the roots of ligularia przewalskii}, journal = {Tetrahedron Letters}, volume = {46}, year = {2005}, month = {AUG}, pages = {5211-5213}, abstract = {

The total synthesis of a natural product noreremophilane has been achieved in just three steps from readily available starting materials. A highly stereo- and regio-selective Diels-Alder reaction was the key step in Our synthesis. (c) 2005 Elsevier Ltd. All rights reserved.

}, doi = {10.1016/j.tetlet.2005.05.130}, author = {Reddy, D. Srinivasa and Palani, K. and Balasubrahmanyam, D. and Kamath, V. B. and Iqbal, Javed} } @article {43222, title = {Mild and efficient method for the synthesis of vinylogous carbamates from alkyl azides}, journal = {Tetrahedron Letters}, volume = {46}, year = {2005}, month = {FEB}, pages = {979-982}, abstract = {A mild and efficient one-pot method for the synthesis of vinylogous carbamates is reported starting from alkyl azides under a hydrogen atmosphere using 10\% Pd/C. The resulting products are useful intermediates for the synthesis of heterocyclic compounds, natural products, and in peptidomimetics. (C) 2004 Elsevier Ltd. All rights reserved.}, doi = {10.1016/j.tetlet.2004.12.047}, author = {Reddy, D. Srinivasa and Rajale, T. V. and Shivakumar, K. and Iqbal, Javed} } @article {43219, title = {Simple procedure for the synthesis of gamma-hydroxy-alpha,beta-(E)-alkenoic esters: formal synthesis of (+)-macrosphelides A and B}, journal = {Tetrahedron Letters}, volume = {46}, year = {2005}, month = {MAR}, pages = {2287-2290}, abstract = {A highly trans-selective conjugate reduction of 7-hydroxy-alpha,beta-alkynoic esters to produce gamma-hydroxy-alpha,beta-(E)-alkenoic esters using LiAlH4 is reported. The application of this methodology is demonstrated by a formal synthesis of the potent cell-cell adhesion inhibitors (+)-macrosphelides A and B. (c) 2005 Elsevier Ltd. All rights reserved.}, author = {Rao, K. Srinivasa and Mukkanti, K. and Reddy, D. Srinivasa and Pal, Manojit and Lqbal, Javed} } @article {43221, title = {Synthesis of small cyclic peptides constrained with 3-(3-aminomethylphenyl)propionic acid linkers using free radical-mediated macrocyclization}, journal = {Tetrahedron Letters}, volume = {46}, year = {2005}, month = {AUG}, pages = {5207-5210}, abstract = {In this letter, we report that small peptides (di- and tri-) having a 3-bromobenzyl group at the C-termini and an acryloyl group at the N-termini undergo an efficient Bu3SnH-AlBN mediated intramolecular free radical cyclization to afford cyclic peptides in good yields. We also propose that these cyclizations are occurring via a pre-organized acyclic structure dictated by a reverse turn (gamma/beta-turn). (c) 2005 Published by Elsevier Ltd.}, doi = {10.1016/j.tetlet.2005.05.115}, author = {Balraju, V. and Reddy, D. Srinivasa and Periasamy, M. and Iqbal, Javed} } @article {43212, title = {Concise asymmetric route to the antibiotic macrolides patulolide A and pyrenophorin}, journal = {Tetrahedron Letters}, volume = {47}, year = {2006}, month = {SEP}, pages = {6623-6626}, abstract = {In this letter, we describe an enantiospecific route to patulolide A and pyrenophorin through the synthesis of known protected seco acid precursors starting from commercially available (S)-ethyl lactate. (c) 2006 Elsevier Ltd. All rights reserved.}, doi = {10.1016/j.tetlet.2006.07.026}, author = {Rao, K. Srinivasa and Reddy, D. Srinivasa and Mukkanti, K. and Pal, Manojit and Iqbal, Javed} } @article {43213, title = {Synthesis of cyclic peptides using a palladium-catalyzed enyne cycloisomerization}, journal = {Tetrahedron Letters}, volume = {47}, year = {2006}, month = {MAY}, pages = {3569-3571}, abstract = {In this letter, we report a palladium-catalyzed enyne cycloisomerization of linear peptides to generate small cyclic peptides embedded with a conjugated 1,3-diene. The utility of these resulting macrocyclic dienes is demonstrated by carrying out [4+2] cycloadditions with dienophiles to generate constrained cyclic peptides with cyclic linkers. (c) 2006 Elsevier Ltd. All rights reserved.}, doi = {10.1016/j.tetlet.2006.03.053}, author = {Balraju, V. and Dev, R. Vasu and Reddy, D. Srinivasa and Iqbal, Javed} } @article {43210, title = {New route to eremophilanes: synthesis of (+/-)-eremophilenolide, (+/-)-eremophiledinone, and (+/-)-deoxyeremopetasidione}, journal = {Tetrahedron Letters}, volume = {49}, year = {2008}, month = {OCT}, pages = {6084-6086}, abstract = {A new and efficient route to the family of eremophilanes is reported. Key steps are the highly stereocontrolled Diels-Alder reaction and aldol condensation to furnish a cis-decalin system with the desired stereochemistry present in the eremophilane family of natural products. This approach is general and was utilized for the synthesis of (+/-)-eremophilenolide, (+/-)-eremophiledinone, and (+/-)-deoxyeremopetasidione. (C) 2008 Elsevier Ltd. All rights reserved.}, doi = {10.1016/j.tetlet.2008.08.006}, author = {Srinivas, P. and Reddy, D. Srinivasa and Kumar, K. Shiva and Dubey, P. K. and Iqbal, Javed and Das, Parthasarathi} } @article {43208, title = {Total synthesis of (+/-)-petasitolone and (+/-)-fukinone}, journal = {Synthesis-Stuttgart}, year = {2009}, month = {NOV}, pages = {3833-3837}, abstract = {An efficient, general, and fully stereocontrolled synthesis of eremophilane-type compounds is disclosed. The approach features a highly diastereoselective Diels-Alder/aldol sequence to give a common intermediate, which is subsequently exploited to produce (+/-)-petasitolone and (+/-)-fukinone in a short sequence.}, doi = {10.1055/s-0029-1218150}, author = {Pasikanti, Srinivas and Reddy, D. Srinivasa and Iqbal, Javed and Dubey, Pramod Kumar and Das, Parthasarathi} } @article {43206, title = {Efficient synthesis of varenicline}, journal = {Tetrahedron Letters}, volume = {51}, year = {2010}, month = {JAN}, pages = {151-152}, abstract = {Synthesis of varenicline the antismoking drug has been achieved in six steps with 10\% overall yield. A Diels-Alder reaction, oxidative cleavage of an olefin and reductive amination remain as key steps in the synthesis (C) 2009 Elsevier Ltd. All rights reserved.}, doi = {10.1016/j.tetlet.2009.10.107}, author = {Pasikanti, Srinivas and Reddy, D. Srinivasa and Venkatesham, B. and Dubey, P. K. and Iqbal, Javed and Das, Parthasarathi} } @article {43205, title = {Enantiospecific synthesis of sex pheromone of the obscure mealybug from pantolactone via tandem conjugate addition/cyclization}, journal = {Tetrahedron Letters}, volume = {51}, year = {2010}, month = {OCT}, pages = {5291-5293}, abstract = {An efficient synthesis of an enantiomer of insect{\textquoteright}s natural pheromone is reported starting from chiral pool D-(-)-pantolactone. Highly stereoselective tandem conjugate addition/cyclization sequence and hydrogenation of exocyclic double bond are the key steps in the present synthesis. (C) 2010 Elsevier Ltd. All rights reserved.}, doi = {10.1016/j.tetlet.2010.07.166}, author = {Hajare, Atul K. and Datrange, Laxmikant S. and Vyas, Samir and Bhuniya, Debnath and Reddy, D. Srinivasa} } @article { ISI:000288848900007, title = {Enantiospecific route to (+)-(1R, 3S)-cis-chrysanthemic acid from (-)-D-pantolactone(1)}, journal = {Synthesis-Stuttgart}, number = {7}, year = {2011}, month = {APR}, pages = {1067-1070}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

In this paper, a novel route for the synthesis of (+)-(1R,3S)-cis-chrysanthemic acid is described. The use of readily available (-)-D-pantolactone as a starting point, application of ring-closing metathesis to form the cyclopentene intermediate, and Haller-Bauer/Grob-type fragmentation to form the target compound are the highlights of the present synthesis.

}, keywords = {alkenes, Metathesis, ring closure, stereoselective synthesis, Wittig reaction}, issn = {0039-7881}, doi = {10.1055/s-0030-1258451}, author = {Hajare, Atul K. and Datrange, Laxmikant S. and Murthy, Y. L. N. and Bhuniya, Debnath and Reddy, D. Srinivasa} } @article {43203, title = {Novel pyrazole-3-carboxamide derivatives as cannabinoid-1 (CB1) antagonists: journey from non-polar to polar amides}, journal = {Bioorganic \& Medicinal Chemistry Letters}, volume = {21}, year = {2011}, month = {JAN}, pages = {562-568}, abstract = {The synthesis and biological evaluation of novel pyrazole-3-carboxamide derivatives as CB1 antagonists are described. As a part of eastern amide SAR, various chemically diverse motifs were introduced. In general, a range of modifications were well tolerated. Several molecules with high polar surface area were also indentified as potent CB1 receptor antagonists. The in vivo proof of principle for weight loss is exemplified with a lead compound from this series. (C) 2010 Elsevier Ltd. All rights reserved.}, doi = {10.1016/j.bmcl.2010.10.055}, author = {Sasmal, Pradip K. and Reddy, D. Srinivasa and Talwar, Rashmi and Venkatesham, B. and Balasubrahmanyam, D. and Kannan, M. and Srinivas, P. and Kumar, K. Shiva and Devi, B. Neelima and Jadhav, Vikram P. and Khan, Sanjoy K. and Mohan, Priya and Chaudhury, Hira and Bhuniya, Debnath and Iqbal, Javed and Chakrabarti, Ranjan} } @article { ISI:000296195400018, title = {Phosphine-mediated synthesis of 1,4-oxazepine- and 1,5-oxazocine-based sugar hybrids from deoxysugar azides}, journal = {Synthesis-Stuttgart}, volume = {21}, number = {21}, year = {2011}, month = {NOV}, pages = {3523-3529}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

An efficient and convenient method was developed for the synthesis of novel 1,4-oxazepine- and 1,5-oxazocine-based sugar hybrids from readily available deoxysugar azides by means of tributylphosphine-mediated tandem reactions. The resulting glycoconjugates might be useful in increasing the diversity of sugar backbones, and could find applications as potential glycomimetics and in drug discovery.

}, keywords = {Alkynes, azides, carbohydrates, heterocycles, oxazepines, oxazocines, Tandem reactions}, issn = {0039-7881}, doi = {10.1055/s-0030-1260218}, author = {Kurhade, Suresh E. and Salunkhe, Videsh T. and Siddaiah, V. and Bhuniya, Debnath and Reddy, D. Srinivasa} } @article { ISI:000286577400023, title = {Synthesis of molluscicidal agent cyanolide a macrolactone from D-(-)-pantolactone}, journal = {Journal of Organic Chemistry}, volume = {76}, number = {3}, year = {2011}, month = {FEB}, pages = {963-966}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

An efficient synthesis of potent molluscicidal agent cyanolide A, a glycosidic 16-membered macrolide, starting from D-(-)-pantolactone is reported. Highly stereoselective aldol, oxa-Michael addition, and Yamaguchi macrolactonization are the key steps in the present synthesis.

}, issn = {0022-3263}, doi = {10.1021/jo101782q}, author = {Hajare, Atul K. and Ravikumar, Velayutham and Khaleel, Shaik and Bhuniya, Debnath and Reddy, D. Srinivasa} } @article { ISI:000293436100018, title = {Synthesis of novel dihydrooxazine and oxazoline based sugar hybrids from sugar azides}, journal = {Tetrahedron Letters}, volume = {52}, number = {33}, year = {2011}, month = {AUG}, pages = {4313-4315}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A convenient one-step method for the synthesis of novel dihydrooxazine and oxazoline based sugar hybrids is reported starting from the readily accessible sugar azides and aldehydes. We have used Aube{\textquoteright}s protocol to achieve this transformation. The resulting glycoconjugates could be used to increase the diversity on the sugar backbone and may find applications as potential glycomimetics and in drug discovery. (C) 2011 Elsevier Ltd. All rights reserved.

}, keywords = {Dihydrooxazine, Glycoconjugate, Hydroxy azide, Oxazoline, Sugar azide, Sugar hybrids}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2011.06.035}, author = {Kurhade, Suresh E. and Ravula, Sudhir and Siddaiah, V. and Bhuniya, Debnath and Reddy, D. Srinivasa} } @article { ISI:000292479300036, title = {Total synthesis of isofregenedadiol}, journal = {Organic Letters}, volume = {13}, number = {14}, year = {2011}, month = {JUL}, pages = {3690-3693}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The first total synthesis of isofregenedadiol, a bicyclic diterpene isolated from H. Viscosum, is reported starting from a D-(-)-pantolactone chiral pool. A one-pot quadruple reaction sequence comprising an enyne ring-closing metathesis/cross-metathesis/Diels-Alder/aromatization for the construction of a target skeleton Is the highlight of the present synthesis.

}, issn = {1523-7060}, doi = {10.1021/ol201336x}, author = {Kurhade, Suresh E. and Sanchawala, Abbas I. and Ravikumar, Velayutham and Bhuniya, Debnath and Reddy, D. Srinivasa} } @article { ISI:000305764600011, title = {Antituberculosis agent diaportheone B: synthesis, absolute configuration assignment, and anti-TB activity of its analogues}, journal = {Organic \& Biomolecular Chemistry}, volume = {10}, number = {28}, year = {2012}, month = {MAY}, pages = {5385-5394}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

First synthesis of diaportheone B, an antituberculosis agent isolated from endophytic fungus Diaporthe sp. P133 is reported using two complementary routes, a one step and a three-step sequence. The absolute configuration of diaportheone B was determined by using X-ray crystal structure analysis of its dibromo derivative. In addition, we have prepared several close analogues of diaportheone B and determined their anti-TB potential using Alamar-blue assay (H(37)Rv).

}, issn = {1477-0520}, doi = {10.1039/c2ob25831e}, author = {Swaroop, Pandrangi Siva and Raut, Gajanan N. and Gonnade, Rajesh G. and Verma, Priyanka and Gokhale, Rajesh S. and Reddy, D. Srinivasa} } @article { ISI:000302810800004, title = {Green synthetic route to antimalarial and antibacterial agent CJ-15,801 and its isomer cis-CJ-15,801}, journal = {RSC Advances}, volume = {2}, number = {9}, year = {2012}, month = {MAR}, pages = {3596-3598}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

An efficient and rapid synthesis of antiplasmodial and antibacterial agent CJ-15,801 and its isomer cis-CJ-15,801 is disclosed. We have made an attempt towards {\textquoteleft}{\textquoteleft}Ideal Synthesis{\textquoteright}{\textquoteright} or a step towards {\textquoteleft}{\textquoteleft}Dial-a-Molecule{\textquoteright}{\textquoteright} by reducing the number of steps, following atom economy, and a green synthetic route.

}, issn = {2046-2069}, doi = {10.1039/c2ra01051h}, author = {Kashinath, K. and Swaroop, Pandrangi Siva and Reddy, D. Srinivasa} } @article { ISI:000312564500027, title = {Studies toward the synthesis of potent anti-inflammatory peptides solomonamides A and B: synthesis of a macrocyclic skeleton and key fragment 4-amino-6-(2 {\textquoteleft}-amino-4 {\textquoteleft}-hydroxyphenyl)-3-hydroxy-2-methyl-6-oxohexanoic acid (AHMOA)}, journal = {Organic Letters}, volume = {14}, number = {24}, year = {2012}, month = {DEC}, pages = {6222-6225}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

A first synthetic effort toward total synthesis of highly potent solomonamides is disclosed. An efficient strategy to synthesize this class of compounds, along with the synthesis of a core macrocycle (shown in red) and the key fragment AHMOA, is described.

}, issn = {1523-7060}, doi = {10.1021/ol303149k}, author = {Kashinath, K. and Vasudevan, N. and Reddy, D. Srinivasa} } @article { ISI:000310947900007, title = {Synthesis of isomeric corniculatolides}, journal = {Tetrahedron Letters}, volume = {53}, number = {47}, year = {2012}, month = {NOV}, pages = {6343-6346}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Synthesis of three natural macrolides 11-O-methylcorniculatolide A, 11-O-methylisocorniculatolide A and isocorniculatolide A is reported using a simple, straight forward and high-yielding route. The present synthesis confirms the assigned molecular structures and provides an access to sufficient quantities of the natural products for the biological evaluation. In addition, we have determined the anti-TB potential of the three natural compounds using Alamar-Blue assay (H(37)Rv) and found no significant inhibitory activity at 100 mu g/ml. Excellent yields, short sequence and useful SAR information are the highlights of the present work. (C) 2012 Elsevier Ltd. All rights reserved.

}, keywords = {Diaryl ether, Isocorniculatolide, Macrocyclization, Mitsunobu reaction, Total synthesis}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2012.09.010}, author = {Raut, Gajanan N. and Chakraborty, Kasturi and Verma, Priyanka and Gokhale, Rajesh S. and Reddy, D. Srinivasa} } @article { ISI:000318001400027, title = {Diverted total syntheses of potent cell adhesion inhibitor peribysin E analogues}, journal = {Organic Letters}, volume = {15}, number = {8}, year = {2013}, month = {APR}, pages = {1894-1897}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Preliminary results from a program aimed at the creation of a focused library of analogues around the natural product peribysin E, a potent biologically active and structurally fascinating molecule, are reported. The total synthesis of (+/-)-peribysin E was accomplished using a short route. Eight new analogues of the natural compound have been accomplished by means of {\textquoteleft}{\textquoteleft}diverted total synthesis{\textquoteright}{\textquoteright} in less than 10 steps. The present effort highlights protecting-group-free total syntheses and the shortest route to access these functionally embellished hydrindanes.

}, issn = {1523-7060}, doi = {10.1021/ol400555m}, author = {Handore, Kishor L. and Reddy, D. Srinivasa} } @article { ISI:000325950600096, title = {Enantiodivergent routes to (+) and (-)-novioses from (-)-pantolactone}, journal = {RSC Advances}, volume = {3}, number = {43}, year = {2013}, month = {AUG}, pages = {20291-20297}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Noviose, a rare sugar moiety present in many biologically interesting molecules such as novobiocin and tiacumicin was obtained through formal synthesis in (+)- and (-)-forms starting from commercially available (-)-pantolactone in an enantiodivergent manner.

}, issn = {2046-2069}, doi = {10.1039/c3ra42891e}, author = {Rajesh, B. M. and Shinde, Madhuri V. and Kannan, M. and Srinivas, Gujjary and Iqbal, Javed and Reddy, D. Srinivasa} } @article { ISI:000328864800072, title = {First total synthesis of hunanamycin A}, journal = {Organic Letters}, volume = {15}, number = {17}, year = {2013}, month = {SEP}, pages = {4556-4559}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The first total synthesis of hunanamycin A, an antibiotic natural product with a pyrido[1,2,3-de]quinoxaline-2,3-dione core from a marine-derived Bacillus hunanensis, is disclosed. The present effort provides access to sufficient amounts of scarce hunanamycin A for further biological evaluation and confirmation of the assigned absolute configuration. In addition, four new analogues of the natural product are reported.

}, issn = {1523-7060}, doi = {10.1021/ol402110e}, author = {Shingare, Rahul D. and Velayudham, R. and Gawade, Jalindar R. and Reddy, D. Srinivasa} } @article { ISI:000320979500046, title = {Syntheses and determination of absolute configurations and biological activities of the enantiomers of the longtailed mealybug pheromone}, journal = {Journal of Organic Chemistry}, volume = {78}, number = {12}, year = {2013}, month = {JUN}, pages = {6281-6284}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Preparation and assignment of absolute configurations to both enantiomers of the sex pheromone of the longtailed mealybug, an irregular monoterpenoid with extraordinary biological activity, has been completed. Comparison of the biological activities of both enantiomers and the racemate in field trials showed that the (S)-(+)-enantiomer was highly attractive to male mealybugs, strongly suggesting that female longtailed mealybugs produce this enantiomer. The (R)-(-)-enantiomer was benign, being neither attractive nor inhibitory.

}, issn = {0022-3263}, doi = {10.1021/jo400491n}, author = {Ramesh, Remya and Swaroop, Pandrangi Siva and Gonnade, Rajesh G. and Thirupath, Choppari and Waterworth, Rebeccah A. and Millar, Jocelyn G. and Reddy, D. Srinivasa} } @article { ISI:000321490900014, title = {Synthesis of a sex pheromone of the longtailed mealybug, pseudococcus longispinus}, journal = {Synthesis-Stuttgart}, volume = {45}, number = {12}, year = {2013}, month = {JUN}, pages = {1689-1692}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

The synthesis of a recently identified and highly active sex pheromone of the longtailed mealybug, Pseudococcus longispinus is reported. A concise synthetic route, use of the under explored Meyer-Schuster rearrangement, Claisen rearrangement, and ring-closing metathesis are the highlights of this work.

}, keywords = {Acylation, Metathesis, pheromones, rearrangement, Total synthesis}, issn = {0039-7881}, doi = {10.1055/s-0033-1338450}, author = {Kurhade, Suresh E. and Siddaiah, V. and Bhuniya, Debnath and Reddy, D. Srinivasa} } @article { ISI:000316693100020, title = {Synthesis of palmyrolide A and its cis-isomer and mechanistic insight into trans-cis isomerisation of the enamide macrocycle}, journal = {Chemical Communications}, volume = {49}, number = {32}, year = {2013}, month = {MAR}, pages = {3342-3344}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Concise and protecting-group free synthesis of ent-palmyrolide A and (-)-cis-palmyrolide A were achieved starting from commercially available (S)-citronellal. The key fragment of palmyrolide A, {\textquoteleft}{\textquoteleft}(5S,7S)-7-hydroxy-5,8,8-trimethylnonanamide{\textquoteright}{\textquoteright}, which makes up the most challenging part of the target molecule, was prepared in just three steps. A plausible mechanism for the trans-cis isomerization of the double bond in the macrocycle has been investigated.

}, issn = {1359-7345}, doi = {10.1039/c3cc40541a}, author = {Philkhana, Satish Chandra and Seetharamsingh, B. and Dangat, Yuvraj B. and Vanka, Kumar and Reddy, D. Srinivasa} } @article { ISI:000340500300065, title = {Access to harmonine, a chemical weapon of ladybird beetles}, journal = {RSC Advances}, volume = {4}, number = {58}, year = {2014}, month = {JUL}, pages = {30923-30926}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

The synthesis of harmonine, a defense alkaloid from the harlequin ladybird is reported by three different routes. The preparation of several new analogs with the same molecular weight and the decoration of gold nanoparticles with harmonines are also part of the present communication.

}, issn = {2046-2069}, doi = {10.1039/c4ra05859c}, author = {Philkhana, Satish Chandra and Dhasaiyan, Prabhu and Bhagavatula L. V. Prasad and Reddy, D. Srinivasa} } @article { ISI:000340696200021, title = {Efforts towards the synthesis of microsporin B: ready access to both the enantiomers of the key amino acid fragment}, journal = {Tetrahedron Letters}, volume = {55}, number = {34}, year = {2014}, month = {AUG}, pages = {4777-4779}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Both the isomers methyl-(2S,8R)-2-((tert-butoxycarbonyl)amino)-8-hydroxydecanoate and methyl-(2S,8S)-2-((tert-butoxycarbonyl)amino)-8-hydroxydecanoate of an unusual amino acid residue and the key fragment of microsporin B are prepared. The key steps include cross metathesis and enzymatic kinetic resolution. In addition, a linear tetrapeptide with desired components towards total synthesis is also reported. (C) 2014 Elsevier Ltd. All rights reserved.

}, keywords = {Cross metathesis, Enzymatic resolution, HDAC inhibitor, Microsporin, Tetrapeptide}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2014.06.093}, author = {Swaroop, Pandrangi Siva and Tripathy, Sibanarayan and Jachak, Gorakhnath R. and Reddy, D. Srinivasa} } @article { ISI:000339493400008, title = {General approach to N-heterocyclic carbenes with a fused tetracyclic core: ligands for suzuki-miyaura cross-coupling reaction}, journal = {European Journal of Organic Chemistry}, number = {21}, year = {2014}, month = {JUL}, pages = {4482-4486}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The synthesis of an N-heterocyclic carbene (NHC) based on a tetracyclic scaffold by using simple, general, and scalable chemistry is disclosed. The developed route is suitable for introducing multiple substitutions on the tetracyclic scaffold. The utility of the present NHC as a ligand in the Suzuki-Miyaura cross-coupling reaction is demonstrated with a low catalyst loading.

}, keywords = {C-C coupling, carbenes, Homogeneous catalysis, N ligands, synthetic methods}, issn = {1434-193X}, doi = {10.1002/ejoc.201402378}, author = {Sutar, Revannath L. and Kumar, Vinod and Shingare, Rahul D. and Thorat, Shridhar and Gonnade, Rajesh G. and Reddy, D. Srinivasa} } @article { ISI:000336844400011, title = {Total synthesis of an anticancer norsesquiterpene alkaloid isolated from the fungus flammulina velutipes}, journal = {Organic \& Biomolecular Chemistry}, volume = {12}, number = {24}, year = {2014}, month = {APR}, pages = {4098-4103}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

The first total synthesis of a norsesquiterpene alkaloid (R)-8-hydroxy-4,7,7-trimethyl-7,8-dihydrocyclo-penta[e]isoindole-1,3(2 H,6H)-dione, isolated from the mushroom-forming fungus Flammulina velutipes, in both racemic and enantiomeric pure forms, is reported. The (-)-enantiomer of the natural product has been synthesized from the D-(-)-pantolactone chiral pool. The synthesis features a one-pot, three-step reaction sequence comprising an enyne RCM/Diels-Alder/aromatization to construct the desired indane skeleton present in the natural product. Our synthesis further confirms the assigned structure and absolute configuration of the natural product.

}, issn = {1477-0520}, doi = {10.1039/c4ob00300d}, author = {Kashinath, K. and Jadhav, Prakash D. and Reddy, D. Srinivasa} } @article { ISI:000346037500028, title = {Total synthesis of deoxy-solomonamide B by mimicking biogenesis}, journal = {Organic Letters}, volume = {16}, number = {23}, year = {2014}, month = {DEC}, pages = {6148-6151}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

A total synthesis of Deoxy-solomonamide B was accomplished starting from tryptophan in an efficient manner by mimicking the proposed biogenetic route. The present synthesis utilizes a crotylation, oxidative cleavage of the indole moiety, and macrolactamization as key steps. The use of the indole nucleus as a masked anthranilic acid unit paves the way for the easy synthesis of related macrocycles and natural products where the ortho-acyl aniline moiety is embedded into them, which otherwise is difficult to synthesize.

}, issn = {1523-7060}, doi = {10.1021/ol503011g}, author = {Vasudevan, N. and Kashinath, K. and Reddy, D. Srinivasa} } @article { ISI:000340517200050, title = {Total synthesis of (+/-)-nardoaristolone B and its analogues}, journal = {Organic Letters}, volume = {16}, number = {16}, year = {2014}, month = {AUG}, pages = {4252-4255}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The first total synthesis of nardoaristolone B, a nor-sesquiterpenoid with an unusual fused ring system and having protective effects on the injury of neonatal rat cardiomyocytes, has been accomplished. Stereoselective synthesis of its novel analogues inlcuding exo-cyclopropyl ring fusion is also part of this disclosure. In addition, an alternate and more efficient one-step method to make a 3/5/6 tricyclic ring system using the Robinson annulation method has been developed toward the generation of a library of compounds around this skeleton.

}, issn = {1523-7060}, doi = {10.1021/ol501949r}, author = {Handore, Kishor L. and Reddy, D. Srinivasa} } @article { ISI:000336844400010, title = {Zinc mediated allylations of chlorosilanes promoted by ultrasound: synthesis of novel constrained sila amino acids}, journal = {Organic \& Biomolecular Chemistry}, volume = {12}, number = {24}, year = {2014}, month = {MAY}, pages = {4093-4097}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

A simple, fast and efficient method for allylation and propargylation of chlorosilanes through zinc mediation and ultrasound promotion is reported. As a direct application of the resulting bis-allylsilanes, three novel, constrained sila amino acids are prepared for the first time. The design and synthesis of the constrained sila analogue of GABA (gamma-amino butyric acid) is a highlight of this work.

}, issn = {1477-0520}, doi = {10.1039/c4ob00294f}, author = {Ramesh, Remya and Reddy, D. Srinivasa} } @article { ISI:000354004400014, title = {Breaking and making of olefins simultaneously using ozonolysis: application to the synthesis of useful building blocks and macrocyclic core of solomonamides}, journal = {Organic Letters}, volume = {17}, number = {9}, year = {2015}, month = {MAY}, pages = {2090-2093}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

A simple and practical one-pot) two-directional approach to access olefinic esters through simultaneous breaking and making of olefins using ozonolysis of alkenyl aryl selenides is disclosed The scope of the method with a variety of example{\textquoteright}s is demonstrated, and the end products obtained here are useful building blocks. As a direct application of the present method,the macrocyclic cote of potent anti-inflammatory natural cyclic peptides, solomonamides, is synthesized.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.5b00637}, author = {Kashinath, K. and Dhara, Santu and Reddy, D. Srinivasa} } @article { ISI:000366429100003, title = {Breaking and making of rings: a method for the preparation of 4-quinolone-3-carboxylic acid amides and the expensive drug ivacaftor}, journal = {European Journal of Organic Chemistry}, number = {34}, year = {2015}, month = {DEC}, pages = {7433-7437}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {

A simple and convenient method to access 4-quinolone-3-carboxylic acid amides from indole-3-acetic acid amides through one-pot oxidative cleavage of the indole ring followed by condensation (Witkop-Winterfeldt type oxidation) was explored. The scope of the method was confirmed with more than 20 examples and was successfully applied to the synthesis of the drug Ivacaftor, the most expensive drug on the market.

}, keywords = {Amides, Drug design, Fused-ring systems, Oxidation, Ozonolysis}, issn = {1434-193X}, doi = {10.1002/ejoc.201501048}, author = {Vasudevan, N. and Jachak, Gorakhnath R. and Reddy, D. Srinivasa} } @article { ISI:000364803200005, title = {Design, synthesis, and identification of silicon incorporated oxazolidinone antibiotics with improved brain exposure}, journal = {ACS Medicinal Chemistry Letters}, volume = {6}, number = {11}, year = {2015}, month = {NOV}, pages = {1105-1110}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Therapeutic options for brain infections caused by pathogens with a reduced sensitivity to drugs are limited. Recent reports on the potential use of linezolid in treating brain infections prompted us to design novel compounds around this scaffold. Herein, we describe the design and synthesis of various oxazolidinone antibiotics with the incorporation of silicon. Our findings in preclinical species suggest that silicon incorporation is highly useful in improving brain exposures. Interestingly, three compounds from this series demonstrated up to a 30-fold higher brain/plasma ratio when compared to linezolid thereby indicating their therapeutic potential in brain associated disorders.

}, keywords = {Antibacterial, brain exposure, linezolid, oxazolidinone, sila analogue}, issn = {1948-5875}, doi = {10.1021/acsmedchemlett.5b00213}, author = {Seetharamsingh, B. and Ramesh, Remya and Dange, Santoshkumar S. and Khairnar, Pankaj V. and Singhal, Smita and Upadhyay, Dilip and Veeraraghavan, Sridhar and Viswanadha, Srikant and Vakkalanka, Swaroop and Reddy, D. Srinivasa} } @article { ISI:000359393500052, title = {Enantiospecific synthesis of both enantiomers of the longtailed mealybug pheromone and their evaluation in a new zealand vineyard}, journal = {Journal of Organic Chemistry}, volume = {80}, number = {15}, year = {2015}, month = {AUG}, pages = {7785-7789}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The irregular monoterpenoid sex pheromone of Pseudococcus longispinus and its enantiomer were prepared from the corresponding bornyl acetates. The use of readily accessible chiral starting materials and lactone lactone rearrangement are the highlights of the present synthesis. The biological activities of the two enantiomers and racemic mixture were tested in a New Zealand vineyard. The (S)-(+)-enantiomer was significantly more attractive to P. longispinus males than the racemic mixture or the (R)-(-)-enantiomer.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.5b01131}, author = {Ramesh, Remya and Bell, Vaughn and Twidle, Andrew M. and Gonnade, Rajesh G. and Reddy, D. Srinivasa} } @article { ISI:000350528300019, title = {First synthesis of nitrosporeusines, alkaloids with multiple biological activities}, journal = {Tetrahedron Letters}, volume = {56}, number = {10}, year = {2015}, month = {MAR}, pages = {1252-1254}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Synthesis of nitrosporeusines A and B, thioester-bearing alkaloids from the Arctic Streptomyces nitrosporeus with exceptional biological activity is disclosed for the first time. In addition, we have prepared another biologically important natural product, maleimycin, in optically pure form using a gram-scale enzymatic resolution method. (C) 2015 Elsevier Ltd. All rights reserved.

}, keywords = {Enzymatic resolution, Influenza H1N1 virus, Maleimycin, Michael reaction, Nitrosporeusine}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2015.01.143}, author = {Philkhana, Satish Chandra and Jachak, Gorakhnath R. and Gunjal, Vidya B. and Dhage, Nagsen M. and Bansode, Ajay H. and Reddy, D. Srinivasa} } @article { ISI:000347229500001, title = {One-pot quadruple/triple reaction sequence: a useful tool for the synthesis of natural products}, journal = {Organic \& Biomolecular Chemistry}, volume = {13}, number = {4}, year = {2015}, month = {OCT}, pages = {970-973}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Multiple reactions in one pot has always been a useful technique for synthetic organic chemists, as it can minimizes solvent usage, time and the number of purification steps when compared to individual multi-step syntheses. In line with this, here in this perspective we discuss a one-pot quadruple/triple reaction sequence comprising an enyne ring-closing metathesis/cross-metathesis/Diels-Alder/aromatization for the synthesis of natural products setting.

}, issn = {1477-0520}, doi = {10.1039/c4ob02143f}, author = {Kashinath, K. and Reddy, D. Srinivasa} } @article { ISI:000364803200006, title = {Silicon incorporated morpholine antifungals: design, synthesis, and biological evaluation}, journal = {ACS Medicinal Chemistry Letters}, volume = {6}, number = {11}, year = {2015}, month = {NOV}, pages = {1111-1116}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Known morpholine class antifungals (fenpropimorph, fenpropidin, and amorolfine) were synthetically modified through silicon incorporation to have 15 sila-analogues. Twelve sila-analogues exhibited potent antifungal activity against different human fungal pathogens such as Candida albicans, Candida glabrata, Candida tropicalis, Cryptococcus neoformans, and Aspergillus niger. Si la-analogue 24 (fenpropimorph analogue) was the best in our hands, which showed superior fungicidal potential than fenpropidin, fenpropimorph, and amorolfine. The mode of action of sila-analogues was similar to morpholines, i.e., inhibition of sterol reductase and sterol isomerase enzymes of ergosterol synthesis pathway.

}, keywords = {Antifungal drugs, Candida albicans, ergosterol biosynthesis, morpholines, sila-analogues}, issn = {1948-5875}, doi = {10.1021/acsmedchemlett.5b00245}, author = {Jachak, Gorakhnath R. and Ramesh, Remya and Sant, Duhita G. and Jorwekar, Shweta U. and Jadhav, Manjusha R. and Tupe, Santosh G. and Deshpande, Mukund V. and Reddy, D. Srinivasa} } @article { ISI:000356927800001, title = {Synthesis of novel N-cyclopentenyl-lactams using the aube reaction}, journal = {Beilstein Journal of Organic Chemistry}, volume = {11}, year = {2015}, month = {JUN}, pages = {1060-1067}, publisher = {BEILSTEIN-INSTITUT}, address = {TRAKEHNER STRASSE 7-9, FRANKFURT AM MAIN, 60487, GERMANY}, abstract = {

A novel and convenient method utilizing the Aube reaction to access a new class of compounds that are similar to carbocyclic nucleosides is reported. The azido alcohol derived from Vince lactam undergoes the Aube reaction with various cyclic ketones to give cyclopentenyl-substituted lactams. Upon dihydroxylation, this affords the N-cyclopentenyl-lactam compounds in racemic form. Given the numerous uses of nucleosides and related compounds, we were interested in the synthesis of carbocylic nucleoside mimics. The attempts and results are described herein.

}, keywords = {Aube reaction, Biological activity, carbocyclic nucleosides, cyclopentenylated lactams, cyclopentylated lactams}, issn = {1860-5397}, doi = {10.3762/bjoc.11.119}, author = {Shinde, Madhuri V. and Ople, Rohini S. and Sangtani, Ekta and Gonnade, Rajesh G. and Reddy, D. Srinivasa} } @article { ISI:000364803200007, title = {Total syntheses and biological evaluation of (+/-)-botryosphaeridione, (+/-)-pleodendione, 4-epi-periconianone B, and analogues}, journal = {ACS Medicinal Chemistry Letters}, volume = {6}, number = {11}, year = {2015}, month = {NOV}, pages = {1117-1121}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The total syntheses of (+/-)-botryosphaeridione, (+/-)-pleodendione, (+/-)-hoaensieremodione, 4-epi-periconianone B, and their analogues have been accomplished for the first time. All the synthesized target compounds were screened in neural anti-inflammatory assays using LPS induced microglia cells (N9). Among them, compounds 1 and 21 were identified as potential lead compounds for further profiling.

}, keywords = {antineuroinflammatoty agents, bohyosphaeridione, Natural product, pleodendione, Total synthesis}, issn = {1948-5875}, doi = {10.1021/acsmedchemlett.5b00241}, author = {Handore, Kishor L. and Jadhav, Prakash D. and Hazra, Bibhabasu and Basu, Anirban and Reddy, D. Srinivasa} } @article { ISI:000352463200009, title = {Total synthesis and structural revision of mycalol, an anticancer natural product from the marine source}, journal = {Organic Letters}, volume = {17}, number = {7}, year = {2015}, month = {APR}, pages = {1652-1655}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The total synthesis of an anticancer (anaplastic thyroid) natural lipid mycalol has been accomplished for the first time. Synthesis of originally proposed structure necessitated the revision of structure in which the position of acetate group moved from C20 to C19 and a change in stereochemistry of the glycerol unit.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.5b00345}, author = {Seetharamsingh, B. and Rajamohanan, P. R. and Reddy, D. Srinivasa} } @article {42902, title = {Enantiospecific formal synthesis of inthomycin C}, journal = {Chemistry Select}, volume = {1}, year = {2016}, month = {MAR}, pages = {495{\textendash}497}, abstract = {

An enantiospecific synthesis of Hatakeyama{\textquoteright}s intermediate enynol has been accomplished in both enantiomeric forms. As these intermediates can be converted to (3R)-inthomycin C and (3S)-inthomycin C through respective enynol intermediates using reported procedures, present effort may be regarded as formal synthesis of inthomycin C in both enantiomeric forms. Our synthesis highlights the use of pantolactone chiral pool and thus reconfirms the previously assigned absolute stereochemistry as 3R to the natural product inthomycin C.

}, doi = {10.1002/slct.201600128}, author = {Athawale, Paresh R. and Kashinath, K. and Reddy, D. Srinivasa} } @article { ISI:000367701900032, title = {First total synthesis of gliomasolide C and formal total synthesis of sch-725674}, journal = {Journal of Organic Chemistry}, volume = {81}, number = {1}, year = {2016}, month = {JAN}, pages = {290-296}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Syntheses of two 14-membered macrolides Sch-725674 and Gliomasolide C are described here. The first total synthesis of Gliomasolide C, the short synthesis of Sch-725674, and regios elective Wacker oxidation of internal olefin are the highlights of this disclosure. In addition, a key macrocyde with orthogonal functionalities was designed and synthesized on a gram scale for the generation of analogues.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.5b02318}, author = {Seetharamsingh, B. and Khairnar, Pankaj V. and Reddy, D. Srinivasa} } @article {42940, title = {GSH Induced controlled release of levofloxacin from a purpose-built prodrug: luminescence response for probing the drug release in escherichia coli and staphylococcus aureus}, journal = {Bioconjugate Chemistry}, volume = {27}, year = {2016}, month = {SEP}, pages = {2062-2070}, abstract = {

Fluoroquinolones are third-generation broad spectrum bactericidal antibiotics and work against both Gram-positive and Gram-negative bacteria. Levofloxacin (L), a fluoroquinolone, is widely used in anti-infective chemotherapy and treatment of urinary tract infection and pneumonia. The main pathogen for urinary tract infections is Escherichia colt, and Streptococcus pneumoniae is responsible for pneumonia, predominantly a lower respiratory tract infection. Poor permeability of L leads to the use of higher dose of this drug and excess drug in the outer cellular fluid leads to central nervous system (CNS) abnormality. One way to counter this is to improve the lipophilicity of the drug molecule, and accordingly, we have synthesized two new Levofloxacin derivatives, which participated in the spatiotemporal release of drug via disulfide bond cleavage induced by glutathione (GSH). Recent studies with Streptococcus mutants suggest that it is localized in epithelial lining fluid (ELF) of the normal lower respiratory tract and the effective [GSH] in ELF is similar to 430 mu M. E. coli typically cause urinary tract infections and the concentration of GSH in porcine bladder epithelium is reported as 0.6 mM for a healthy human. Thus, for the present study we have chosen two important bacteria (Gram + ve and Gram - ve), which are operational in regions having high extracellular GSH concentration. Interestingly, this supports our design of new lipophilic Levofloxacin based prodrugs, which released effective drug on reaction with GSH. Higher lipophilicity favored improved uptake of the prodrugs. Site specific release of the drug (L) could be achieved following a glutathione mediated biochemical transformation process through cleavage of a disulfide bond of these purpose-built prodrugs. Further, appropriate design helped us to demonstrate that it is possible also to control the kinetics of the drug release from respective prodrugs. Associated luminescence enhancement helps in probing the release of the drug from the prodrug in bacteria and helps in elucidating the mechanistic pathway of the transformation. Such an example is scarce in the contemporary literature.

}, doi = {10.1021/acs.bioconjchem.6b00324}, author = {Pal, Suman and Ramu, Vadde and Taye, Nandaraj and Mogare, Devraj G. and Yeware, Amar M. and Sarkar, Dhiman and Reddy, D. Srinivasa and Chattopadhyay, Samit and Das, Amitava} } @article {42901, title = {Identification of noreremophilane-based inhibitors of angiogenesis using zebrafish assays}, journal = {Organic \& Biomolecular Chemistry}, volume = {14}, year = {2016}, month = {OCT}, pages = {1569-1578}, author = {Muthukumarasamy, Kalai Mangai and Handore, Kishor L. and Kakade, Dipti N. and Shinde, Madhuri V. and Ranjan, Shashi and Kumar, Naveen and Sehrawat, Seema and Sachidanandan, Chetana and Reddy, D. Srinivasa} } @article { ISI:000379577800033, title = {Molecules with O-acetyl group protect protein glycation by acetylating lysine residues}, journal = {RSC Advances}, volume = {6}, number = {70}, year = {2016}, month = {JUL}, pages = {65572-65578}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Pharmaceutical intervention for reduction of advanced glycation end products (AGEs) is considered as a therapeutic strategy to attenuate the pathogenesis of diabetes. Many molecules have been reported to possess antiglycation activity, one such example is acetylsalicylic acid (aspirin). It protects proteins from glycation by acetylating the lysine residues. Therefore, in this study we have synthesized and screened molecules containing free N-acetyl, O-acetyl and acetophenone groups. All the selected molecules in this study showed glycation inhibition but interestingly, only molecules with O-acetyl but not N-acetyl and acetophenone groups were capable of acetylating lysine residue. Furthermore, we have demonstrated that pre-acetylation or aspirin treatment prior to the induction of diabetes helps in reducing HbA1c and AGE formation in the streptozotocin induced diabetic mice. Hence pre-acetylation may have an additional therapeutic efficacy of reducing AGE levels in vivo. Incorporation of O-acetyl group into anti-diabetic molecules could be a useful strategy, as it may have an additive effect in reducing AGEs. Identification of such novel acetylating agents represents a new area in the drug discovery process.

}, issn = {2046-2069}, doi = {10.1039/c6ra11313c}, author = {Vannuruswamy, Garikapati and Jagadeeshaprasad, Mashanipalya G. and Kashinath, K. and Kesavan, Suresh K. and Bhat, Shweta and Korwar, Arvind M. and Chougale, Ashok D. and Boppana, Ramanamurthy and Reddy, D. Srinivasa and Kulkarni, Mahesh J.} } @article { ISI:000380599800018, title = {Multi-gram scale synthesis of hunanamycin A, an antibiotic natural product from the marine source}, journal = {Tetrahedron Letters}, volume = {57}, number = {32}, year = {2016}, month = {AUG}, pages = {3662-3663}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A simple, practical, and biomimetic approach to access antibiotic natural product hunanamycin A starting from readily available inexpensive material Riboflavin is disclosed here. The present synthesis consists of three operationally simple, protecting group free steps and it is far superior when compared with the previous route. Using this route one can make multi-gram quantities of the natural product which will help in further biological assays, in particular exploring the potential of treating food infections. (C) 2016 Elsevier Ltd. All rights reserved.

}, keywords = {Antibacterial, Biomimetic synthesis, Gram scale synthesis, Natural product, Riboflavin}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2016.07.003}, author = {Shingare, Rahul D. and Farhana, Sa Ada and Reddy, D. Srinivasa} } @article {42900, title = {Repurposing of a drug scaffold: identification of novel sila analogues of rimonabant as potent antitubercular agents}, journal = {European Journal of Medicinal Chemistry}, volume = {122}, year = {2016}, month = {OCT}, pages = {723-730}, abstract = {

The structural similarity between an MmpL3 inhibitor BM212, and a cannabinoid receptor modulator rimonabant, prompted us to investigate the anti-tubercular activity of rimonabant and its analogues. Further optimization, particularly through incorporation of silicon into the scaffold, resulted in new compounds with significant improvement in anti-tubercular activity against Mycobacterium tuberculosis (H37Rv). The sila analogue 18a was found to be the most potent antimycobacterial compound (MIC, 31 ng/mL) from this series with an excellent selectivity index. (C) 2016 Elsevier Masson SAS. All rights reserved.

}, doi = {10.1016/j.ejmech.2016.07.009}, author = {Ramesh, Remya and Shingare, Rahul D. and Kumar, Vinod and Anand, Amitesh and Swetha, B. and Veeraraghavan, Sridhar and Viswanadha, Srikant and Ummanni, Ramesh and Gokhale, Rajesh S. and Reddy, D. Srinivasa} } @article {42897, title = {Solution-phase synthesis of the macrocyclic core of teixobactin}, journal = {European Journal of Organic Chemistry}, volume = {25}, year = {2016}, month = {SEP}, pages = {4289-4293}, abstract = {

Towards the total chemical synthesis of the exceptionally potent antibiotic teixobactin, we synthesized the macrocyclic core of a natural product by using a solution-phase approach. The gramscale synthesis of L-allo-enduracididine and Shiina macrolactonization are highlights of the present disclosure.

}, author = {Dhara, Santu and Gunjal, Vidya B. and Handore, Kishor L. and Reddy, D. Srinivasa} } @article {42896, title = {Synthesis and biological evaluation of palmyrolide a macrocycles as sodium channel blockers towards neuroprotection}, journal = {Organic \& Biomolecular Chemistry}, volume = {14}, year = {2016}, month = {AUG}, pages = {8457-8473}, abstract = {

Palmyrolide A is a neuroprotective macrolide isolated by Gerwick and coworkers in 2010. This natural product is known to suppress neuronal spontaneous calcium ion oscillations through its voltage-gated sodium channel blocking ability which is of significant interest in CNS drug discovery. Herein, we give a detailed account on total synthesis of (+)-palmyrolide A and synthesis of a focused library of macrocycles around the scaffold, followed by their biological evaluation. Use of the chiral pool approach, Zhu{\textquoteright}s oxidative homologation, access to unnatural cis-palmyrolide A, preparation of 18 new analogues and identification of macrolides with improved sodium channel blocking activity are the important features of the present paper. As a measure of potency as voltage-gated sodium channel blockers, all the synthesized analogues were profiled for their ability to inhibit the veratridine-stimulated Na+ influx in murine primary neuronal cultures. Four macrocycles were found to be more potent or comparable to that of the natural product (-)-palmyrolide A. The most potent compound from this series 20 was structurally simplified and readily accessible in good quantities for further biological profiling.

}, author = {Philkhana, Satish Chandra and Mehrotra, Suneet and Murray, Thomas F. and Reddy, D. Srinivasa} } @article { ISI:000377612300008, title = {Synthesis of revised structure of klaivanolide (acetylmelodorinol)}, journal = {Arkivoc}, number = {2}, year = {2016}, month = {OCT}, pages = {116-122}, publisher = {ARKAT USA INC}, address = {C/O ALAN R KATRITZKY, UNIV FLORIDA, DEPT CHEMISTRY, PO BOX 117200, GAINESVILLE, FL 32611 USA}, abstract = {

Klaivanolide (acetylmelodorinol) is an anti-leishmanial/anti-trypanosomal agent isolated from Uvaria klaineana and the structure was originally assigned as a 7-membered lactone with extended conjugation and S-configuration at the lactone junction. Very recently, the structure of klaivanolide was revised as previously known compound acetylmelodorinol. Now, we have synthesized the revised structure in racemic form using a short route.

}, keywords = {acetylmelodorinol, Klaivanolide, leishmaniasis, Natural product}, issn = {1551-7004}, doi = {10.3998/ark.5550190.p009.231}, author = {Raut, Gajanan N. and Wagh, Sachin B. and Reddy, D. Srinivasa} } @article { ISI:000382768400020, title = {Total synthesis of (-)-nardoaristolone B}, journal = {European Journal of Organic Chemistry}, number = {22}, year = {2016}, month = {AUG}, pages = {3804-3808}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {

A stereoselective total synthesis of (-)-Nardoaristolone B, a nor-aristolane sesquiterpenoid natural product with an unusual 3/5/6 tricyclic ring system is described. The highlights of the present work includes use of (+)-(R)-Pulegone as a chiral-pool starting material, ring-closing metathesis, allylic oxidation and stereoselective cyclopropanation. In addition, a new analogue of Nardoaristolone B (minor product from the final step) was isolated in pure form and fully characterized with the help of single-crystal X-ray analysis.

}, keywords = {Chiral pool, cyclopropanation, Nardoaristolone B, Natural products, Total synthesis}, issn = {1434-193X}, doi = {10.1002/ejoc.201600538}, author = {Ople, Rohini S. and Handore, Kishor L. and Kamat, Nidhi S. and Reddy, D. Srinivasa} } @article { ISI:000379455300035, title = {Total synthesis of the marine natural product solomonamide B necessitates stereochemical revision}, journal = {Organic Letters}, volume = {18}, number = {13}, year = {2016}, month = {JUL}, pages = {3178-3181}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The first total synthesis of the proposed structure of solomonamide B has been achieved. However, the H-1 and C-13 NMR spectral data of the synthesized compound was not exactly matching with that of the natural solomonamide B. This prompted us to revise the originally proposed structure, in particular, the stereochemistry of the nonpeptide part, which was confirmed by its total synthesis. During the course of the synthesis, we have developed an interesting hydroxy group directed Wacker oxidation of internal olefins in a macrocyclic setting.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.6b01395}, author = {Kashinath, K. and Jachak, Gorakhnath R. and Athawale, Paresh R. and Marelli, Udaya Kiran and Gonnade, Rajesh G. and Reddy, D. Srinivasa} } @article {43833, title = {Access to fused tricyclic gamma-butyrolactones, a natural product -like scaffold}, journal = {Journal Of Organic Chemistry}, volume = {82}, year = {2017}, month = {JUL}, pages = {7614-7620}, type = {Article}, abstract = {Serendipitous findings of an acid mediated skeletal rearrangement of bicydo-beta-ketoester having cyclopropyl ring to access fused tricyclic gamma-butyrolactones has been described. This novel transformation has been optimized to 30 mol\% p-toluenesulfonic acid (p-TSA) in toluene using Dean Stark apparatus, where the aldol condensation, cyclopropyl ring opening followed by cyclization took place in a single-pot operation. The resulting tricyclic compounds are interesting chemotype with natural product resemblance and may find useful applications in the future.}, doi = {10.1021/acs.joc.7b00794}, author = {Kalmode, Hanuman P. and Handore, Kishor L. and Reddy, D. Srinivasa} } @article {43473, title = {Determination of the absolute configuration of gliomasolide D through total syntheses of the C-17 epimers}, journal = {Journal of Natural Products}, volume = {80}, year = {2017}, month = {FEB}, pages = {560-564}, abstract = {The absolute configuration at C-17, the carbon bearing the distal hydroxy group of the 14-membered natural product gliomasolide D, was assigned as R by comparison of C-13 NMR shifts and specific rotation values of the epimers at C-17. The first total synthesis of gliomasolide D along with its C-17 epimer, regioselective macrocyclization (18 membered vs 14 membered), and regioselective Wacker oxidation are highlights of the present work.}, doi = {10.1021/acs.jnatprod.6b00926}, author = {Seetharamsingh, B. and Ganesh, Routholla and Reddy, D. Srinivasa} } @article {43744, title = {Identification and synthesis of mycalol analogues with improved potency against anaplastic thyroid carcinonia cell lines}, journal = {Journal of Natural Products}, volume = {80}, year = {2017}, month = {APR}, pages = {1125-1133}, type = {Article}, abstract = {The marine metabolite mycalol (1) has a specific inhibitory activity on cells of anaplastic thyroid carcinoma (ATC), a very aggressive and rare cancer that does not have effective conventional therapy. In this study, we describe six new related analogues (2-7) that differ in the length of the terminal alkyl residue and the presence of acetate or 3S-hydroxybutyrate (3S)-3HB as a substituent at C-19. Despite the structural{\textquoteright} analogies, some of the new members were significantly more-cytotokic than 1 on cell lines,derivecl from human ATC. Structures inclusive of the 2{\textquoteright}R,3R,4S,7R,8S,19R absolute configuration were asigned to 2-7 on the basis of detailed spectroscopic analysis, synthesis of different isomers, and application of ECD and Mosher{\textquoteright}s methods. This work led to the identification of mycal61-578 (3) as the most potent analogue, with an IC50 of 2.3 mu M on FRO cells:}, doi = {10.1021/acs.jnatprod.7b00043}, author = {Cutignano, Adele and Seetharamsingh, B. and D{\textquoteright}Angelo, Daniela and Nuzzo, Genoveffa and Khairnar, Pankaj V. and Fusco, Alfredo and Reddy, D. Srinivasa and Fontana, Angelo} } @article {43826, title = {Identification of new anti-inflammatory agents based on nitrosporeusine natural products of marine origin}, journal = {European Journal of Medicinal Chemistry}, volume = {135}, year = {2017}, month = {JUL}, pages = {89-109}, type = {Article}, abstract = {Nitrosporeusines A and B are two recently isolated marine natural products with novel skeleton and exceptional biological profile. Interesting antiviral activity of nitrosporeusines and promising potential in curing various diseases, evident from positive data from various animal models, led us to investigate their anti-inflammatory potential. Accordingly, we planned and synthesized nitrosporeusines A and B in racemic as well as enantiopure forms. The natural product synthesis was followed by preparation of several analogues, and all the synthesized compounds were evaluated for in vitro and in vivo anti-inflammatory potential. Among them, compounds 25, 29 and 40 significantly reduced levels of nitric oxide (NO), reactive oxygen species (ROS) and pro-inflammatory cytokines. In addition, these compounds suppressed several pro-inflammatory mediators including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear factor-kappa B (NF -kappa B), and thereby can be emerged as potent anti-inflammatory compounds. Furthermore, all possible isomers of lead compound 25 were synthesized, characterized and profiled in same set of assays and found that one of the enantiomer (-)-25a was superior among them. (C) 2017 Elsevier Masson SAS. All rights reserved.}, doi = {10.1016/j.ejmech.2017.04.015}, author = {Philkhana, Satish Chandra and Verma, Abhishek Kumar and Jachak, Gorakhnath R. and Hazra, Bibhabasu and Basu, Anirban and Reddy, D. Srinivasa} } @article {45690, title = {Route to benzimidazol-2-ones via decarbonylative ring contraction of quinoxalinediones: application to the synthesis of flibanserin, A drug for treating hypoactive sexual desire disorder in women and marine natural product hunanamycin analogue}, journal = {ACS Omega}, volume = { 2 }, year = {2017}, month = {AUG}, pages = {5137-5141}, type = {Article}, abstract = {

A simple and practical method to access a variety of benzimidazol-2-ones is reported here. A series of N-alkylsubstituted benzimidazol-2-ones were synthesized by decarbonylative ring contraction starting from corresponding quinoxalinediones for the first time. The utility of the method has been demonstrated by synthesizing recently approved controversial drug flibanserin (Addyi) and a urea analogue of marine antibiotic natural product hunanamycin-A.

}, doi = {10.1021/acsomega.7b00819}, author = {Shingare, Rahul D. and Kulkarni, Akshay S. and Sutar, Revannath L. and Reddy, D. Srinivasa} } @article {43531, title = {Total synthesis of natural fregenedadiol and its diacetate, rearranged labdanes with aromatized B ring}, journal = {Tetrahedron Letters}, volume = {58}, year = {2017}, month = {MAR}, pages = {1262-1264}, abstract = {Labdane based natural products are most abundant and widely distributed in nature with many compounds exhibiting exceptional biological properties. Fregenedadiol is a bicyclic diterpene isolated from Halimium viscosum and represents a new carbon skeleton fregenedane with its B ring aromatized. Here, we report a total synthesis of this interesting natural product using one-pot Diels-Alder/aromatization sequence and selective hydrogenolysis as key steps. (C) 2017 Elsevier Ltd. All rights reserved.}, doi = {10.1016/j.tetlet.2017.02.010}, author = {Philkhana, Satish Chandra and Reddy, D. Srinivasa} } @article {45352, title = {Evaluating antimalarial efficacy by tracking glycolysis in Plasmodium falciparum using NMR spectroscopy}, journal = {Scientific Reports}, volume = { 8}, year = {2018}, month = {DEC}, type = {Article}, abstract = {Glucose is an essential nutrient for Plasmodium falciparum and robust glycolytic activity is indicative of viable parasites. Using NMR spectroscopy, we show that P. falciparum infected erythrocytes consume similar to 20 times more glucose, and trophozoites metabolize similar to 6 times more glucose than ring stage parasites. The glycolytic activity, and hence parasite viability, can be measured within a period of 2 h to 5 h, using this method. This facilitates antimalarial bioactivity screening on ring and trophozoite stage parasites, exclusively. We demonstrate this using potent and mechanistically distinct antimalarial compounds such as chloroquine, atovaquone, cladosporin, DDD107498 and artemisinin. Our findings indicate that ring stage parasites are inherently more tolerant to antimalarial inhibitors, a feature which may facilitate emergence of drug resistance. Thus, there is a need to discover novel antimalarial compounds, which are potent and fast acting against ring stage parasites. The NMR method reported here can facilitate the identification of such molecules.}, issn = {2045-2322}, doi = {10.1038/s41598-018-36197-3}, author = {Shivapurkar, Rupali and Hingamire, Tejashri and Kulkarni, Akshay S. and Rajamohanan, P. R. and Reddy, D. Srinivasa and Shanmugam, Dhanasekaran} } @article {44648, title = {Multi-step continuous flow synthesis of the cystic fibrosis medicine ivacaftor}, journal = {Reaction Chemistry \& Engineering}, volume = {3}, year = {2018}, month = {AUG}, pages = {520-526}, abstract = {

A continuous flow ozonolysis method combined with a multi-step flow sequence is developed for the synthesis of the drug ivacaftor for the first time. Safe ozonolysis, a continuous flow quadruple reaction to construct a quinolone scaffold, and inline extraction followed by continuous phase separation are the key features of the present work. The feasibility of using a continuous mixed flow reactor, commonly referred to as a continuous stirred tank reactor (CSTR), is also investigated for the relatively slow reaction step. The current integrated multi-step flow synthesis can produce 7.2 g of the drug ivacaftor per day on a laboratory scale, which is sufficient to treat 50 patients per day. The present route can also be used as a general route for the synthesis of other related drugs such as quinolone antibiotics.

}, issn = {2058-9883}, doi = {10.1039/c8re00025e}, author = {Vasudevan, N. and Sharma, Mrityunjay K. and Reddy, D. Srinivasa and Kulkarni, Amol A.} } @article {45474, title = { Nitrosporeusine analogue ameliorates Chandipura virus induced inflammatory response in CNS via NF kappa b inactivation in microglia}, journal = {PLOS Neglected Tropical Diseases}, volume = {12}, year = {2018}, month = {JUL}, type = {Article}, abstract = {Chandipura Virus (CHPV), a negative-stranded RNA virus belonging to the Rhabdoviridae family, has been previously reported to bring neuronal apoptosis by activating several factors leading to neurodegeneration. Following virus infection of the central nervous system, microglia, the ontogenetic and functional equivalents of macrophages in somatic tissues gets activated and starts secreting chemokines, thereby recruiting peripheral leukocytes into the brain parenchyma. In the present study, we have systemically examined the effect of CHPV on microglia and the activation of cellular signalling pathways leading to chemokine expression upon CHPV infection. Protein and mRNA expression profiles of chemokine genes revealed that CHPV infection strongly induces the expression of CXC chemokine ligand 10 (CXCL10) and CC chemokine ligand 5 (CCL5) in microglia. CHPV infection triggered the activation of signalling pathways mediated by mitogen-activated protein kinases, including p38, JNK 1 and 2, and nuclear factor kappa B (NF-kappaB). CHPV-induced expression of CXCL10 and CCL5 was achieved by the activation of p38 and NF-kappaB pathways. Considering the important role of inflammation in neurodegeneration, we have targeted NF-kappaB using a newly synthesised natural product nitrosporeusine analogue and showed incapability of microglial supernatant of inducing apoptosis in neurons after treatment.}, issn = {1935-2735}, doi = {10.1371/journal.pntd.0006648}, author = {Verma, Abhishek Kumar and Waghmare, Trushnal S. and Jachak, Gorakhnath R. and Philkhana, Satish Chandra and Reddy, D. Srinivasa and Basu, Anirban} } @article {44376, title = {Quest for novel chemical entities through incorporation of silicon in drug scaffolds}, journal = {Journal of Medicinal Chemistry}, volume = {61}, year = {2018}, month = {MAY}, pages = {3779-3798}, abstract = {In order to optimize a lead molecule for further development, bioisosteric replacements are generally adopted as one of the strategies. Silicon appears to be the right choice as a carbon isostere because of the similarity in chemical properties. Silicon can be strategically introduced in a molecule to modulate its druglike properties, providing medicinal chemists with an unconventional strategy for replacing a carbon atom. Silicon can also be introduced to replace other heteroatoms and can act as a surrogate of functional groups such as olefin and amide as well. The present Perspective focuses on the opportunities that silicon incorporation offers in drug discovery, with an emphasis on case studies where introduction of silicon has created a benefit over its analog. We have tried to highlight all the recent developments in the field and briefly discuss the challenges associated with them.}, doi = {10.1021/acs.jmedchem.7b00718}, author = {Ramesh, Remya and Reddy, D. Srinivasa} } @article {44618, title = {Specific stereoisomeric conformations determine the drug potency of cladosporin scaffold against malarial parasite}, journal = {Journal of Medicinal Chemistry}, volume = {61}, year = {2018}, month = {JUL}, pages = {5664-5678}, abstract = {

The dependence of drug potency on diastereomeric configurations is a key facet. Using a novel general divergent synthetic route for a three-chiral center antimalarial natural product cladosporin, we built its complete library of stereoisomers (cladologs) and assessed their inhibitory potential using parasite-, enzyme-, and structure-based assays. We show that potency is manifest via tetrahyropyran ring conformations that are housed in the ribose binding pocket of parasite lysyl tRNA synthetase (KRS). Strikingly, drug potency between top and worst enantiomers varied 500-fold, and structures of KRS-cladolog complexes reveal that alterations at C3 and C10 are detrimental to drug potency whereas changes at C3 are sensed by rotameric flipping of glutamate 332. Given that scores of antimalarial and anti-infective drugs contain chiral centers, this work provides a new foundation for focusing on inhibitor stereochemistry as a facet of antimicrobial drug development.

}, issn = {0022-2623}, doi = {10.1021/acs.jmedchem.8b00565}, author = {Das, Pronay and Babbar, Palak and Malhotra, Nipun and Sharma, Manmohan and Jachak, Goraknath R. and Gonnade, Rajesh G. and Shanmugam, Dhanasekaran and Harlos, Karl and Yogavel, Manickam and Sharma, Amit and Reddy, D. Srinivasa} } @article {44494, title = {Targeted phenotypic screening in plasmodium falciparum and toxoplasma gondii reveals novel modes of action of medicines for malaria venture malaria box molecules}, journal = {mSphere}, volume = {3}, year = {2018}, month = {JAN}, pages = { e00534-17}, type = {Journal Article}, abstract = {The Malaria Box collection includes 400 chemically diverse small molecules with documented potency against malaria parasite growth, but the underlying modes of action are largely unknown. Using complementary phenotypic screens against Plasmodium falciparum and Toxoplasma gondii, we report phenotype-specific hits based on inhibition of overall parasite growth, apicoplast segregation, and egress or host invasion, providing hitherto unavailable insights into the possible mechanisms affected. First, the Malaria Box library was screened against tachyzoite stage T. gondii and the half-maximal effective concentrations (EC50s) of molecules showing >=80\% growth inhibition at 10 {\textmu}M were determined. Comparison of the EC50s for T. gondii and P. falciparum identified a subset of 24 molecules with nanomolar potency against both parasites. Thirty molecules that failed to induce acute growth inhibition in T. gondii tachyzoites in a 2-day assay caused delayed parasite death upon extended exposure, with at least three molecules interfering with apicoplast segregation during daughter cell formation. Using flow cytometry and microscopy-based examinations, we prioritized 26 molecules with the potential to inhibit host cell egress/invasion during asexual developmental stages of P. falciparum. None of the inhibitors affected digestive vacuole integrity, ruling out a mechanism mediated by broadly specific protease inhibitor activity. Interestingly, five of the plasmodial egress inhibitors inhibited ionophore-induced egress of T. gondii tachyzoites. These findings highlight the advantage of comparative and targeted phenotypic screens in related species as a means to identify lead molecules with a conserved mode of action. Further work on target identification and mechanism analysis will facilitate the development of antiparasitic compounds with cross-species efficacy.}, issn = {23795042}, doi = {10.1128/mSphere.00534-17}, author = {Subramanian, Gowtham}, editor = {Belekar, Meenakshi A.} } @article {45485, title = {Total synthesis and biological evaluation of cell adhesion inhibitors peribysin A and B: structural revision of peribysin B}, journal = {Organic letters }, volume = { 20}, year = {2018}, month = {NOV}, pages = {7003-7006}, type = {Article }, abstract = {Total synthesis of potent cell-adhesion inhibitors peribysins A and B has been accomplished for the first time in racemic form. A Diels-Alder/aldol sequence to build the skeleton and decoration of the desired functionalities of the targeted natural products using highly stereoselective operations are the highlights. The structures of synthesized peribysins were fully characterized using spectral data and single-crystal X-ray analysis. Through this total synthesis, the initially proposed structure of peribysin B has been revised. Furthermore, the cell-adhesion inhibition potential of the scaffold (two peribysins + three analogues) was confirmed using anti-adhesion assay.}, issn = {1523-7060}, doi = { 10.1021/acs.orglett.8b02838}, author = {Kalmode, Hanuman P. and Handore, Kishor L. and Rajput, Raveena and Shaikh, Samir R. and Gonnade, Rajesh G. and Kulkarni, Kiran A. and Reddy, D. Srinivasa} } @article {45380, title = {Total synthesis of an anticancer natural product (+/-)-peharmaline A and its analogues}, journal = { European Journal of Organic Chemistry}, year = {2018}, month = {DEC}, pages = {6453-6456}, type = {Article}, abstract = {

First total synthesis of a rare beta-carboline-vasicinone hybrid alkaloid (+/-)-peharmaline A has been accomplished in just 3 steps starting from known compounds. Stereoselective Pictet-Spengler reaction to nitrogenated tertiary carbon center and one-pot construction of the tricyclic skeleton of vasicinone are the highlights of present synthesis. We have also synthesized structurally close analogues of the natural product by following the developed route.

}, issn = {1434-193X}, doi = {10.1002/ejoc.201800949}, author = {Kulkarni, Akshay S. and Shingare, Rahul D. and Dandela, Rambabu and Reddy, D. Srinivasa} } @article {45356, title = {Total synthesis of the potent anti-inflammatory natural product solomonamide A along with structural revision and biological activity evaluation}, journal = {Organic \& Biomolecular Chemistry}, volume = {16}, year = {2018}, month = {DEC}, pages = {9138-9142}, type = {Article }, abstract = {Herein, we report the total synthesis of solomonamide A along with its structural revision for the first time. The natural product possesses very potent anti-inflammatory activity, and it contains a macrocyclic peptide having four consecutive stereocenters on an unnatural amino acid component. The key features in the present synthesis include the application of an Evans aldol reaction, ligand-free Heck macrocyclization and chemoselective oxidations. The challenging task of fixing the stereochemistry of OH at the C5-position was accomplished with the help of DFT calculations, applying a quantum-mechanical (QM)/NMR combined approach. Biological evaluation in a mouse paw edema model revealed that a low dose (0.3 mg kg(-1)) of the synthesized solomonamide A showed 74\% reduction at 6 h, which was comparable to a high dose (10 mg kg(-1)) standard drug dexamethasone effect (75\% at 6 h). Thus, we further confirmed the revised structure of solomonamide A.}, issn = {1477-0520}, doi = { 10.1039/c8ob02713g}, author = {Jachak, Gorakhnath R. and Athawale, Paresh R. and Agarwal, Heena and Barthwal, Manoj Kumar and Lauro, Gianluigi and Bifulco, Giuseppe and Reddy, D. Srinivasa} } @article {46324, title = {Access to a stereoisomer library of solomonamide macrocycles}, journal = {Chemistry-An Asian Journal}, year = {2019}, month = {OCT}, type = {Article; Early Access}, abstract = {

In an attempt towards understanding stereo-structure activity relationships (SSARs), we have prepared eight possible stereoisomers of solomonamide macrocycles, in particular, by changing the stereochemical pattern of non-peptide fragment AHMOA. Here, we have demonstrated different ways to construct three contiguous chiral centers present in solomonamide B macrocycle using substrate/reagent-controlled methods. These methods involve Brown crotylation, NHK reaction and Evans aldol addition as key steps to synthesize key non-peptide fragment. Further, these non-peptide fragments were converted to their corresponding macrocycles via ligand-free intramolecular Heck reaction.

}, keywords = {Crotylation, Heck reaction, Inflammation, Macrocycles, Stereochemistry}, issn = {1861-4728}, doi = {10.1002/asia.201901075}, author = {Jachak, Gorakhnath R. and Athawale, Paresh R. and Choudhury, Rahul and Kashinath, K. and Reddy, D. Srinivasa} } @article {46137, title = {Neural anti-inflammatory natural product periconianone A: total synthesis and biological evaluation}, journal = {European Journal of Organic Chemistry}, year = {2019}, month = {APR }, pages = {2376-2381}, type = {Article}, abstract = {

Total synthesis of periconianone A, an eremophilane-type sesquiterpenoid with impressive neural anti-inflammatory potential, has been accomplished. Diels-Alder/aldol strategy to construct tetrahydro-naphthalene-2,6-dione scaffold, allylic oxidation of dienone using DBU/O-2 and postulated biomimetic aldol reaction to construct 6/6/6 tricyclic system are the highlights of the present synthesis. Furthermore, the synthesized (+/-)-periconianone A and two close analogs were tested for their neural anti-inflammatory activity using various assays. In the course of our study we found a structurally simplified analog is superior to (+/-)-periconianone A.

}, keywords = {Aldol, Allylic oxidation, Biological evaluation, Cytotoxicity, Diels-Alder, Periconianone A}, issn = {1434-193X}, doi = {10.1002/ejoc.201900048}, author = {Kalmode, Hanuman P. and Patil, Suhag S. and Handore, Kishor L. and Athawale, Paresh R. and Dandela, Rambabu and Verma, Abhishek Kumar and Basu, Anirban and Reddy, D. Srinivasa} } @article {46275, title = {Route to access imidazol[1,5-a]indole-1,3-diones and pyrrolo[1,2-c]imidazole-1,3-diones}, journal = {Organic \& Biomolecular Chemistry}, volume = {17}, year = {2019}, month = {SEP}, pages = {8384-8390}, type = {Article}, abstract = {

A novel and practical route to synthesize imidazol[1,5-a]indoles and pyrrolo[1,2-c]imidazoles via N-H functionalization has been developed. Indole-2-carboxylic acid or pyrrole-2-carboxylic acid with diverse aniline groups and carbonyldiimidazole (CDI), in the presence of a base under microwave conditions, resulted in imidazol[1,5-a]indoles and pyrrolo[1,2-c]imidazoles, respectively. The present method is free of work-up and no need for column chromatography. Both title scaffolds can serve as useful heterocyclic scaffolds in medicinal chemistry as such, or they can be used as building blocks to construct different classes of useful compounds.

}, doi = {10.1039/c9ob01462d}, author = {Rao, Ramana Sreenivasa and Shajan, Fere Joseph and Reddy, D. Srinivasa} } @article {46163, title = {Scalable synthesis of cladosporin}, journal = {Tetrahedron Letters}, volume = {60}, year = {2019}, month = {MAR }, pages = {831-833}, type = {Article}, abstract = {

Cladosporin, a secondary metabolite isolated from fungal sources like Cladosporium cladosporioides and Aspergillus flavus was found to exhibit selective nano-molar activity against malarial parasite Plasmodium falciparum by inhibiting parasitic protein biosynthesis. In addition, this natural product has a broad range of bioactivities including, antiparasitic, antifungal, antibacterial as well as plant growth inhibition. However, it has limited availability from the natural sources for further development. Herein, we report a modified and improved synthetic route which led us to produce this potent natural product in a gram scale. Conversion of the undesired diastereomer to desired one via Mitsunobu inversion of secondary alcohol and carbon monoxide insertion reaction towards the construction of isocoumarin unit are the key features of the present synthesis. (C) 2019 Elsevier Ltd. All rights reserved.

}, keywords = {Anti-malarials, Cladosporin, Mitsunobu, Total synthesis}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2019.02.012}, author = {Das, Pronay and Mankad, Yash and Reddy, D. Srinivasa} } @article {46212, title = {Synthesis of chiral tetrahydrofuran building blocks from pantolactones: application in the synthesis of empagliflozin and amprenavir analogs}, journal = {Europen Journal of Organic Chemistry}, year = {2019}, month = {JUL}, type = {Article}, abstract = {

Chiral 4,4-dimethyl tetrahydrofuran (THF) derivatives were synthesized from commercially available D-(-)/ l-(+) pantolactones, which can serve as chiral building blocks in medicinal chemistry. In addition, two of the synthesized building blocks were utilized for the synthesis of new amprenavir (HIV protease inhibitor) and empagliflozin (anti-diabetic) analogs. The synthesized analogs may have beneficial effects in terms of pharmacokinetics and modulation of bioactivity.

}, doi = {10.1002/ejoc.201900718}, author = {Athawale, Paresh R and Kumari, Neeta and Kashinath, K and Reddy, D. Srinivasa} } @article {46175, title = {Targeted phenotypic screening in plasmodium falciparum and toxoplasma gondii reveals novel modes of action of medicines for malaria venture malaria box molecules (vol 3, e00534-17, 2018)}, journal = {MSphere}, volume = {4}, year = {2019}, month = {APR}, pages = {e00159-19}, type = {Correction}, issn = {2379-5042}, doi = {10.1128/mSphere.00159-19}, author = {Subramanian, Gowtham and Belekar, Meenakshi A. and Shukla, Anurag and Tong, Jie Xin and Sinha, Ameya and Chu, Trang T. T. and Kulkarni, Akshay S. and Preiser, Peter R. and Reddy, D. Srinivasa and Tan, Kevin S. W. and Shanmugam, Dhanasekaran and Chandramohanadas, Rajesh} } @article {46058, title = {Total synthesis of Met(10)-teixobactin}, journal = {Tetrahedron Letters}, volume = {60}, year = {2019}, month = {JUL }, pages = {1909-1912}, type = {Article}, abstract = {

The total synthesis of cyclic depsipeptide Met(10)-teixobactin in solution-phase is described. Teixobactin is a structurally and mechanistically novel antimicrobial peptidic natural product with very impressive activities against Gram-positive pathogens. It happens to possess an L-allo-enduracididine (End) residue as part of macrocyclic ring which is not readily accessible. In this report, we have used serine ligation strategy as the key step to prepare an analogue of teixobactin where End being replaced with a readily available amino acid methionine. (C) 2019 Elsevier Ltd. All rights reserved.

}, keywords = {antibiotic, Cyclic tetrapeptides, Serine ligation, Teixobactin}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2019.06.027}, author = {Gunjal, Vidya B. and Reddy, D. Srinivasa} } @article {46931, title = {DFT/NMR approach for the configuration assignment of groups of stereoisomers by the combination and comparison of experimental and predicted sets of data}, journal = {Journal of Organic Chemistry}, volume = {85}, year = {2020}, month = {MAR}, pages = {3297-3306}, type = {Article}, abstract = {

Quantum mechanical/nuclear magnetic resonance (NMR) approaches are widely used for the configuration assignment of organic compounds generally comparing one cluster of experimentally determined data (e.g., C-13 NMR chemical shifts) with those predicted for all possible theoretical stereoisomers. More than one set of experimental data, each related to a specific stereoisomer, may occur in some cases, and the accurate stereoassignments can be obtained by combining the experimental and computed data. We introduce here a straightforward methodology based on the simultaneous analysis, combination, and comparison of all sets of experimental/calculated C-13 chemical shifts for aiding the correct configuration assignment of groups of stereoisomers. The comparison of the differences between the calculated/experimental chemical shifts instead of the shifts themselves led to the advantage of avoiding errors arising from calibration procedures, reducing systematic errors, and highlighting the most diagnostic differences between calculated and experimental data. This methodology was applied on a tetrad of synthesized cladosporin stereoisomers (cladologs) and further corroborated on a tetrad of pochonicine stereoisomers, obtaining the correct correspondences between experimental and calculated sets of data. The new MAE(Delta Delta delta) parameter, useful for indicating the best fit between sets of experimental and calculated data, is here introduced for facilitating the stereochemical assignment of groups of stereoisomers.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.9b03129}, author = {Lauro, Gianluigi and Das, Pronay and Riccio, Raffaele and Reddy, D. Srinivasa and Bifulco, Giuseppe} } @article {46649, title = {FeCl3-catalyzed oxidative decarboxylation of aryl/heteroaryl acetic acids: preparation of selected API impurities}, journal = {Organic \& Biomolecular Chemistry}, volume = {18}, year = {2020}, month = {NOV }, pages = {8459-8466}, type = {Article}, abstract = {

There is an ever-increasing demand for impurity compounds for use in impurity profiling as regulatory agencies seek information during registration. Herein, we report the FeCl3-catalyzed oxidative decarboxylation of aryl- and heteroaryl acetic acids to the corresponding carbonyl compounds. A variety of useful aldehydes and ketones were prepared in a simple one-pot transformation by employing an environmentally benign, low-cost, and readily available iron salt. The utility of this method has been demonstrated by preparing five valuable API impurities including a multi-gram-scale synthesis of ketorolac impurity B for the first time.

}, issn = {1477-0520}, doi = {10.1039/d0ob01790f}, author = {Gangadurai, Chinnakuzhanthai and Illa, Giri Teja and Reddy, D. Srinivasa} } @article {46888, title = {Overturning the peribysin family natural products isolated from periconia byssoides OUPS-N133: synthesis and stereochemical revision of peribysins A, B, C, F, and G}, journal = {Organic Letters}, volume = {22}, year = {2020}, month = {APR}, pages = {3104-3109}, type = {Article}, abstract = {

Herein we report the stereochemical revision of peribysins A, B, C, F, and G, guided by enantiospecific total synthesis starting from (+)-nootkatone. Furthermore, we reconfirmed the absolute stereochemistry of peribysin Q The highlights of the synthesis are enone transposition and kinetic iodination resulting in separation of diastereomers. Our findings coupled with synthetic and biological data previously reported by Danishefsky{\textquoteright}s group suggest that the original stereochemistries of peribysins A, B, C, F, and G were misassigned.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.0c00857}, author = {Athawale, Paresh R. and Kalmode, Hanuman P. and Motiwala, Zenia and Kulkarni, Kiran A. and Reddy, D. Srinivasa} } @article {46820, title = {Synthesis of alpha-ketoamides using potassium superoxide (KO2) as an oxidizing agent}, journal = {Tetrahedron}, volume = {76}, year = {2020}, month = {JUN }, pages = {131262}, type = {Article}, abstract = {

A simple and convenient method for the synthesis of alpha-ketoamides by the oxidation of aryl acetamides using potassium superoxide (KO2) as an oxidizing agent is disclosed here. The scope of the developed method is successfully tested with fifteen substrates. In addition, the utility of method has been demonstrated by synthesizing an orexin receptor antagonist, a medicinally interesting compound. (C) 2020 Published by Elsevier Ltd.

}, keywords = {alpha-Ketoamide, Orexin receptor, Oxidation, Potassium superoxide (KO2)}, issn = {0040-4020}, doi = {10.1016/j.tet.2020.131262}, author = {Vasudevan, N. and Routholla, Ganesh and Illa, Giri Teja and Reddy, D. Srinivasa} } @article {46644, title = {Teixobactin: a paving stone toward a new class of antibiotics?}, journal = {Journal of Medicinal Chemistry}, volume = {63}, year = {2020}, month = {NOV }, pages = {12171-12195}, type = {Article}, abstract = {

Antimicrobial resistance is a serious threat to human health worldwide, prompting research efforts on a massive scale in search of novel antibiotics to fill an urgent need for a remedy. Teixobactin, a macrocyclic depsipeptide natural product, isolated from uncultured bacteria (Elef theria terrae), displayed potent activity against several Gram-positive pathogenic bacteria. The distinct pharmacological profile and interesting structural features of teixobactin with nonstandard amino acid (three Damino acids and L-allo-enduracididine) residues attracted several research groups to work on this target molecule in search of novel antibiotics with new mechanism. Herein, we present a comprehensive and critical perspective on immense possibilities offered by teixobactin in the domain of drug discovery. Efforts made by various research groups since its isolation are discussed, highlighting the molecule{\textquoteright}s considerable potential with special emphasis on replacement of amino acids. Critical analysis of synthetic efforts, SAR studies, and the way forward are provided hereunder.

}, issn = {0022-2623}, doi = {10.1021/acs.jmedchem.0c00173}, author = {Gunjal, Vidya B. and Thakare, Ritesh and Chopra, Sidharth and Reddy, D. Srinivasa} } @article {46631, title = {Total synthesis and absolute configuration determination of Ktedonoketone, a benzenoid metabolite from Thermophilic bacterium}, journal = {Tetrahedron Letters}, volume = {61}, year = {2020}, month = {NOV }, pages = {152526}, type = {Article}, abstract = {

The successful total synthesis of both enantiomers of ktedonoketone allowed us to decipher an unambiguous assignment of absolute configuration of the natural product. The concise synthesis highlights Wacker oxidation and aldol condensation as key steps. In addition to this, the current synthetic route is suitable to access a library of compounds on the similar skeleton as one can use readily available amino acids and Grignard reagents as variants. (C) 2020 Elsevier Ltd. All rights reserved.

}, keywords = {Absolute configuration, Ktedonoketone, Total synthesis, Wacker oxidation}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2020.152526}, author = {Dandawate, Monica and Choudhury, Rahul and Krishna, Gamidi Rama and Reddy, D. Srinivasa} } @article {46671, title = {Biological process of lysine-tRNA charging is therapeutically targetable in liver cancer}, journal = {Liver International}, volume = {41}, year = {2021}, month = {JAN }, pages = {206-219}, type = {Article }, abstract = {

Background \& Aims Mature transfer RNAs (tRNA) charged with amino acids decode mRNA to synthesize proteins. Dysregulation of translational machineries has a fundamental impact on cancer biology. This study aims to map the tRNAome landscape in liver cancer patients and to explore potential therapeutic targets at the interface of charging amino acid with tRNA. Methods Resected tumour and paired tumour-free (TFL) tissues from hepatocellular carcinoma (HCC) patients (n = 69), and healthy liver tissues from organ transplant donors (n = 21), HCC cell lines, and cholangiocarcinoma (CC) patient-derived tumour organoids were used. Results The expression levels of different mature tRNAs were highly correlated and closely clustered within individual tissues, suggesting that different members of the tRNAome function cooperatively in protein translation. Interestingly, high expression of tRNA-Lys-CUU in HCC tumours was associated with more tumour recurrence (HR 1.1;P = .022) and worse patient survival (HR 1.1;P = .0037). The expression of Lysyl-tRNA Synthetase (KARS), the enzyme catalysing the charge of lysine to tRNA-Lys-CUU, was significantly upregulated in HCC tumour tissues compared to tumour-free liver tissues. In HCC cell lines, lysine deprivation, KARS knockdown or treatment with the KARS inhibitor cladosporin effectively inhibited overall cell growth, single cell-based colony formation and cell migration. This was mechanistically mediated by cell cycling arrest and induction of apoptosis. Finally, these inhibitory effects were confirmed in 3D cultured patient-derived CC organoids. Conclusions The biological process of charging tRNA-Lys-CUU with lysine sustains liver cancer cell growth and migration, and is clinically relevant in HCC patients. This process can be therapeutically targeted and represents an unexplored territory for developing novel treatment strategies against liver cancer.

}, keywords = {Cladosporin, liver cancer, lysine, Lysyl-tRNA Synthetase, tRNA-Lys-CUU, tRNAome}, issn = {1478-3223}, doi = {10.1111/liv.14692}, author = {Zhang, Ruyi and Noordam, Lisanne and Ou, Xumin and Ma, Buyun and Li, Yunlong and Das, Pronay and Shi, Shaojun and Liu, Jiaye and Wang, Ling and Li, Pengfei and Verstegen, Monique M. A. and Reddy, D. Srinivasa and van Der Laan, Luc J. W. and Peppelenbosch, Maikel P. and Kwekkeboom, Jaap and Smits, Ron and Pan, Qiuwei} } @article {47678, title = {DBU/O-2-mediated oxidation of dienones}, journal = {Journal of Organic Chemistry}, volume = {86}, year = {2021}, month = {JUL }, pages = {9200-9205}, type = {Article}, abstract = {Herein, we describe a DBU/O-2-promoted novel method for oxidation of dienones to 2,6-dione derivatives. The reaction involves treatment of a dienone with DBU in acetonitrile employing molecular oxygen as the oxidant. Metal free conditions and an eco-friendly reagent are the striking features of this protocol. This transformation proceeds through a peroxide intermediate that upon Kornblum-DeLaMare rearrangement produces 2,6-diones. The method was successfully utilized for the synthesis of (+/-)-pleodendione with improved yields versus those of the traditional PDC-TBHP method.}, issn = {0022-3263}, doi = {10.1021/acs.joc.1c00529}, author = {Athawale, Paresh R. and Kalmode, Hanuman P. and Reddy, D. Srinivasa} } @article {47093, title = {Herbicidal bio-assay of isocladosporin enantiomers and determination of its plausible absolute configuration}, journal = {Journal of Antibiotics}, volume = {74}, year = {2021}, month = {APR}, pages = {280-284}, type = {Article}, abstract = {

A fungal metabolite, isocladosporin was isolated from natural fungus, Cladosporium cladosporioides in the mid of 90s. Due to the lack of optical rotation of isolated natural product sample, the absolute configuration of the natural product remained undetermined for more than two decades. Herein, we demonstrated an SAR study of enantiomers of isocladosporin in herbicidal bio-assay against wheat coleoptile. Using this study as a comparative tool we further proposed the plausible absolute configuration of natural isocladosporin for the first time. The assigned configuration was also supported through biogenetic precursors.

}, issn = {0021-8820}, doi = {10.1038/s41429-020-00391-1, Early Access Date = FEB 2021}, author = {Mankad, Yash and Das, Pronay and Pathan, Ejaj and Deshpande, V. M. and Reddy, D. Srinivasa} } @article {47806, title = {Identification of a novel series of potent organosilicon mosquito repellents}, journal = {ACS Omega}, volume = {6}, year = {2021}, month = {NOV}, pages = {31236-31243}, type = {Article}, abstract = {Mosquito control by personal protection is one of the most efficient ways of curtailing deadly diseases such as malaria and dengue with the potential to save millions of lives per year. DEET (N,N-diethyl-3-methyl benzamide) is currently considered as the gold standard for mosquito repellents, being used for the past several decades. Control by DEET, however, is being threatened by emerging resistance among mosquitoes. To address this concern and also to improve protection times, we synthesized a novel series of 25 silicon-containing acyl piperidines using acid{\textendash}amine coupling protocol and tested their activity against Aedes aegypti in mosquito-repellent assays. Several compounds from this series appear to possess good mosquito-repellent properties. Most notably, at 0.5 mg/cm2 concentrations, the mean protection time for NDS100100 was 756 min, which was higher than that of DEET (616 min). The details of design, synthesis, and biological evaluation are discussed herein.}, doi = {10.1021/acsomega.1c04961}, author = {Kulkarni, Akshay S. and Ramesh, Remya and Walia, Safal and Sayyad, Shahebaz I. and Gathalkar, Ganesh B. and Balamkundu, Seetharamsing and Joshi, Manali and Sen, Avalokiteswar and Reddy, D. Srinivasa} } @article {47680, title = {One-pot oxidation of secondary alcohols to alpha-hydroxy ketones: application to synthesis of oxoaplysinopsin D, E, F, \& G}, journal = {European Journal of Organic Chemistry}, volume = {2021}, year = {2021}, month = {APR }, pages = {2188-2192}, type = {Article}, abstract = {A simple one-pot transformation of secondary alcohols to alpha-hydroxy ketones using pyridinium dichromate (PDC) in DMF has been developed and substrate scope tested with 25 compounds of hydantoin derivatives. Using this method, we have devised a common dihydroxy intermediate and synthesized four natural products oxoaplysinopsins D, E, F, and G for the first time.}, keywords = {alpha-Hydroxylation, Hydantoin, Natural product, Oxoaplysinopsin, Retro-aldol}, issn = {1434-193X}, doi = {10.1002/ejoc.202100184}, author = {Kulkarni, Akshay S. and Ramesh, Eagala and Reddy, D. Srinivasa} } @article {47423, title = {Scalable, sustainable and catalyst-free continuous flow ozonolysis of fatty acids}, journal = {Green Chemistry}, volume = {23}, year = {2021}, month = {MAR}, pages = {2391-2396}, type = {Article}, abstract = {

A simple and efficient catalyst-free protocol for continuous flow synthesis of azelaic acid is developed from the renewable feedstock oleic acid. An ozone and oxygen mixture was used as the reagent for oxidative cleavage of double bond without using any metal catalyst or terminal oxidant. The target product was scaled up to more than 100 g with 86\% yield in a white powder form. Complete recycling and reuse of the solvent were established making it a green method. The approach is significantly energy efficient and also has a very small chemical footprint. The methodology has been successfully tested with four fatty acids making it a versatile platform that gives value addition from renewable resources.

}, issn = {1463-9262}, doi = {10.1039/d0gc04021e}, author = {Atapalkar, Ranjit S. and Athawale, Paresh R. and Reddy, D. Srinivasa and Kulkarni, Amol A.} } @article {47691, title = {Separation of a diastereomeric diol pair using the mechanical properties of crystals}, journal = {Crystengcomm}, volume = {23}, year = {2021}, month = {OCT}, pages = {7056-7060}, type = {Article}, abstract = {We report the separation of a (2S,3R/S)-3-ethyl-1-phenylhex-5-ene-2,3-diol (ephd) diastereomeric pair with visually indistinguishable acicular morphologies based on their mechanical responses, which is found to be more efficient than conventional separation methods. Furthermore, the molecular crystals of (2S,3R)-ephd show elastic deformation, while (2S,3S)-ephd fractures in a brittle manner under similar conditions.}, doi = {10.1039/d1ce01055g}, author = {Gamidi, Rama Krishna and Dandawate, Monica and Choudhury, Rahul and Tothadi, Srinu and Nangia, Ashwini and Reddy, D. Srinivasa} } @article {47699, title = {Synthesis and biological evaluation of hoshionolactam-based compounds}, journal = {European Journal of Organic Chemistry}, volume = {2021}, year = {2021}, month = {APR }, pages = {2212-2218}, type = {Article}, abstract = {In search of novel antitrypanosomal agents based on hoshinolactam (IC50=3.9 nM), we disclose the synthesis and biological evaluations of 14 different analogues of the natural product using combinations of different acids and lactams. Antitrypanosomal activity assays revealed that the synthesized analogues were less potent than the parent natural product.}, keywords = {Hoshinolactam, Ozonolysis, Parasitic diseases, Trypanosoma}, issn = {1434-193X}, doi = {10.1002/ejoc.202001588}, author = {Jachak, Gorakhnath R. and Elizebath, Drishya and Shukla, Anurag and Shanmugam, Dhanasekaran and Reddy, D. Srinivasa} } @article {47672, title = {Total synthesis of a hypothetical macroketone of migrastatin}, journal = {European Journal of Organic Chemistry}, volume = {2021}, year = {2021}, month = {JUN }, pages = {3050-3053}, type = {Article}, abstract = {Danishefsky{\textquoteright}s macroketone, a simplified analogue of natural product Migrastatin, is one of the lead compounds with potent cancer cell migration inhibition potential. Different biological assays suggest fascin protein as the potential target. Although it was indicated through X-ray co-crystallography where the concerned macroketone analogue was found to bind in the actin-binding sites of fascin, there was a structural discrepancy, as the X-ray co-crystal structure suggested an E-olefin along with inversion of methyl stereochemistry from that of Danishefsky{\textquoteright}s macroketone. Here, we have accomplished the total synthesis of the {\textquoteleft}hypothetical macroketone{\textquoteright} for the first time. The TiCl4 mediated vinylogous Mukaiyama aldol reaction is the key step in present synthesis.}, keywords = {Hypothetical mecroketon, Metastasis, Migrastatin, RCM, vinylogous Mukaiyama aldol reaction (VMAR)}, issn = {1434-193X}, doi = {10.1002/ejoc.202100484}, author = {Choudhury, Rahul and Reddy, D. Srinivasa} } @article {47402, title = {Total synthesis of twelve membered resorcyclic acid lactones, (R)-penicimenolide A, (R)-resorcyclide and (R)-dihydroresorcyclide}, journal = {Tetrahedron}, volume = {85}, year = {2021}, month = {APR}, pages = {132059}, type = {Article}, abstract = {

Resorcyclic Acid Lactones or RALs are a class of fungal secondary polyketides isolated from a variety of fungal strains like Lasiodiplodia theobromae, Penicillium sp., Syncephalastrum racemosum etc. This class of macrocyclic lactones are found to exhibit a broad spectrum of biological activities and are of significant synthetic importance. Herein, we report the first total synthesis of (R)-penicimenolide A, twelve membered RAL (RAL12) isolated from Penicillium sp. (NO. SYP-F-7919). Besides, we also report the total synthesis of two other members, namely, (R)-trans-resorcyclide and (R)-dihydroresorcyclide. In the course of synthesis, we have utilized ring closing metathesis (RCM) as the key step in constructing the core macrolactone scaffold. (C) 2021 Elsevier Ltd. All rights reserved.

}, keywords = {Macrocycle, Natural product, organic synthesis, Total synthesis}, issn = {0040-4020}, doi = {10.1016/j.tet.2021.132059}, author = {Das, Pronay and Reddy, D. Srinivasa} } @article {47683, title = {Tuning of alpha-silyl carbocation reactivity into enone transposition: application to the synthesis of peribysin D, E-volkendousin, and E-guggulsterone}, journal = {Organic Letters}, volume = {23}, year = {2021}, month = {SEP }, pages = {6642-6647}, type = {Article}, abstract = {A reliable method for enone transposition has been developed with the help of silyl group masking. Enantio-switching, substituent shuffling, and Z-selectivity are the highlights of the method. The developed method was applied for the first total synthesis of peribysin D along with its structural revision. Formal synthesis of E-guggulsterone and E-volkendousin was also claimed using a short sequence.}, issn = {1523-7060}, doi = {10.1021/acs.orglett.1c02173}, author = {Athawale, Paresh R. and Zade, Vishal M. and Krishna, Gamidi Rama and Reddy, D. Srinivasa} } @article {48411, title = {Antibiotic natural product hunanamycin A: Lead identification towards anti-Salmonella agents}, journal = {European Journal of Medicinal Chemistry}, volume = {236}, year = {2022}, month = {JUN}, pages = {114245}, type = {Article}, abstract = {

Design and synthesis of library of compounds around the antibiotic natural product hunanamycin A scaffold and their biological evaluation are disclosed here. These efforts resulted in identification of a lead compound 36, which is a structurally simplified analogue of original hunanamycin A with impressive activity against Salmonella enterica and possesses other druggable properties. In addition, no acute oral toxicity was observed for compound 36 in Swiss albino mice dosed up to 2 g/kg. It has the potential to be developed for the treatment of food infections caused by Salmonella. (c) 2022 Published by Elsevier Masson SAS.

}, keywords = {Antibiotic natural product, Hunanamycin A, Riboflavin synthase, Salmonella, Structure activity relationship}, issn = {0223-5234}, doi = {10.1016/j.ejmech.2022.114245}, author = {Shingare, Rahul D. and MacMillan, John B. and Reddy, D. Srinivasa} } @article {48235, title = {Kupyaphores are zinc homeostatic metallophores required for colonization of Mycobacterium tuberculosis}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {119}, year = {2022}, month = {FEB}, pages = {e2110293119}, type = {Article}, abstract = {

Mycobacterium tuberculosis (Mtb) endures a combination of metal scarcity and toxicity throughout the human infection cycle, contributing to complex clinical manifestations. Pathogens counteract this paradoxical dysmetallostasis by producing specialized metal trafficking systems. Capture of extracellular metal by siderophores is a widely accepted mode of iron acquisition, and Mtb iron-chelating siderophores, mycobactin, have been known since 1965. Currently, it is not known whether Mtb produces zinc scavenging molecules. Here, we characterize low-molecular-weight zinc-binding compounds secreted and imported by Mtb for zinc acquisition. These molecules, termed kupyaphores, are produced by a 10.8 kbp biosynthetic cluster and consists of a dipeptide core of ornithine and phenylalaninol, where amino groups are acylated with isonitrilecontaining fatty acyl chains. Kupyaphores are stringently regulated and support Mtb survival under both nutritional deprivation and intoxication conditions. A kupyaphore-deficient Mtb strain is unable to mobilize sufficient zinc and shows reduced fitness upon infection. We observed early induction of kupyaphores in Mtb-infected mice lungs after infection, and these metabolites disappeared after 2 wk. Furthermore, we identify an Mtb-encoded isonitrile hydratase, which can possibly mediate intracellular zinc release through covalent modification of the isonitrile group of kupyaphores. Mtb clinical strains also produce kupyaphores during early passages. Our study thus uncovers a previously unknown zinc acquisition strategy of Mtb that could modulate host-pathogen interactions and disease outcome.

}, keywords = {metallophore, nutritional immunity, tuberculosis, zinc}, issn = {0027-8424}, doi = {10.1073/pnas.2110293119}, author = {Mehdiratta, Kritee and Singh, Shubham and Sharma, Sachin and Bhosale, Rashmi S. and Choudhury, Rahul and Masal, Dattatraya P. and Manocha, Alzu and Dhamale, Bhushan Dilip and Khan, Naseem and Asokachandran, Vivekanand and Sharma, Pooja and Ikeh, Melanie and Brown, Amanda C. and Parish, Tanya and Ojha, Anil K. and Michael, Joy Sarojini and Faruq, Mohammed and Medigeshi, Guruprasad R. and Mohanty, Debasisa and Reddy, D. Srinivasa and Natarajan, Vivek T. and Kamat, Siddhesh S. and Gokhale, Rajesh S.} } @article {48068, title = {Postmodification of voxelotor (GBT 440) via [Rh]-catalyzed cross dehydrogenative coupling with olefins br}, journal = {Bioorganic \& Medicinal Chemistry Letters}, volume = {77}, year = {2022}, month = {DEC}, pages = {129022}, type = {Article}, abstract = {

The directed Rh(III)-catalyzed cross dehydrogenative coupling of the pyrazole unit of the GBT-440 scaffold has been explored with simple as well as conjugated olefins to synthesize post-functionalized GBT-440 analogues. The screening of these synthesized compounds for improving the oxygen binding efficiency of the hemoglobin isolated from the sickled red blood cells revealed that some of these compounds are as good as GBT-440.

}, keywords = {CDC Coupling, GBT-440 (Voxelotor), Rh(III) catalysis, sickle cell anemia}, issn = {0960-894X}, doi = {10.1016/j.bmcl.2022.129022}, author = {Kalshetti, Rupali G. and Rajput, Raveena and Motiwala, Zenia and Reddy, D. Srinivasa and Kulkarni, Kiran A. and V. Ramana, Chepuri} } @article {48160, title = {Ready access to benzannulated [5,5]-oxaspirolactones using Au(III)-catalyzed cascade cyclizations}, journal = {Journal of Organic Chemistry}, volume = {87}, year = {2022}, month = {MAR}, pages = {3025-3041}, type = {Article}, abstract = {

This work showcases an unprecedented Au(III)-catalyzed cascade cyclization of 2-(4-hydroxyalkynyl)benzoates to access benzannulated [5,5]-oxaspirolactones related to biologically active natural products. This reaction proceeds through an initial 5-endo-dig mode of hydroalkoxylation of the alkynol segment to give the oxocarbenium species (via cyclic enol-ether) followed by the addition of carboxylate onto the oxocarbenium that delivers the oxaspirolactone scaffold. While testing this method{\textquoteright}s scope, we found that the steric and electronic environment of the hydroxyl group could alter the reaction pathway that delivers isochromenone through a competitive 6-endo-dig mode of attack of the carboxylate onto the tethered alkyne.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.1c02843}, author = {Mankad, Yash and Thorat, Sagar S. and Das, Pronay and Krishna, Gamidi Rama and Kontham, Ravindar and Reddy, D. Srinivasa} } @article {48143, title = {Ready access to densely substituted furans using Tsuji-Wacker type cyclization}, journal = {Journal of Organic Chemistry}, volume = {87}, year = {2022}, month = {JAN }, pages = {556-568}, type = {Article}, abstract = {

A competent method for the construction of highly substituted furans catalyzed by Pd(II) and Cu(II) chloride has been developed. The method provides easy access to di-, tri-, and tetrasubstituted furans from corresponding diols with relatively mild conditions in a unified strategy. The developed method has been successfully tested with more than 25 substrates, which resulted in furans of multiple substitution patterns with up to 84\% isolated yields.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.1c02567}, author = {Masal, Dattatraya P. and Choudhury, Rahul and Singh, Aman and Reddy, D. Srinivasa} } @article {48097, title = {Total synthesis of 12, 13-dibenzyl-banistenoside B and analogs}, journal = {European Journal of Organic Chemistry}, volume = {2022}, year = {2022}, month = {MAY}, pages = {e202200222}, type = {Article}, abstract = {

Banistenosides A and B possessing a unique {\textquoteleft}{\textquoteleft}azepino(1,2-a)tetrahydro-beta-carboline{\textquoteright}{\textquoteright} carbon framework were isolated from the stem of Banisteriopsis caapi and showed MAO-A inhibition. Herein, we report the total synthesis of dibenzyl derivative of the untouched natural product in the last two decades, Banistenoside B. The key steps involve construction of 6.5.6.7 tetracyclic core using Pictet-Spengler reaction and intramolecular amide coupling. The stereoselective glycation was achieved through Hotha{\textquoteright}s protocol using gold catalyst, and silver triflate in the late stage of synthesis. The stereochemistry of most of the essential compounds were confirmed by X-ray crystallography.

}, keywords = {Au-catalyst, Multiple steps total synthesis, Natural products, Pictet-Spengler reaction, Wittig reaction}, issn = {1434-193X}, doi = {10.1002/ejoc.202200222}, author = {Patil, Suhag S. and Jachak, Gorakhnath R. and Krishna, Gamidi Rama and Argade, Narshinha P. and Reddy, D. Srinivasa} } @article {48985, title = {Comprehensive study on solomonamides: total synthesis, stereochemical revision, and SAR studies toward identification of simplified lead}, journal = {Journal of Organic Chemistry}, volume = {88}, year = {2023}, month = {DEC }, pages = {17088-17133}, type = {Article}, abstract = {

Solomonamides, a pair of macrocyclic peptide natural products originating from marine sources, have garnered significant attention within the synthetic community owing to their marked anti-inflammatory efficacy and intricate molecular architectures. In this paper, we present a very detailed investigation into solomonamides, including the challenges associated with the total synthesis, the evolution of our synthetic strategies, structural reassignment, synthesis of all possible stereoisomeric macrocycles, biological assessment, structure-activity relationship (SAR) studies, etc. Within the ambit of this total synthesis, diverse strategies for macrocyclization were rigorously explored, encompassing the Friedel-Crafts acylation, cyclization involving the aniline NH2 moiety, macrolactamization utilizing Gly-NH2, and Heck macrocyclization methodologies. In addition, an array of intriguing chemical transformations were devised, including but not limited to photo-Fries rearrangement, Wacker oxidation, ligand-free Heck macrocyclization, oxidative cleavage of indole, synthesis of contiguous stereocenters via substrate/reagent-controlled protocols, and simultaneous making and breaking of olefinic moieties. The findings of this investigation revealed a structurally simplified lead compound. Remarkably, the lead compound, while possessing structural simplification in comparison to the intricate solomonamide counterparts, demonstrates equipotent in vivo anti-inflammatory efficacy.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.3c01987}, author = {Jachak, Gorakhnath R. and Kashinath, K. and Vasudevan, N. and Athawale, Paresh R. and Choudhury, Rahul and Dange, Santoshkumar S. and Agarwal, Heena and Barthwal, Manoj Kumar and Reddy, D. Srinivasa} } @article {48443, title = {Developing a mealybug pheromone monitoring tool to enhance IPM practices in New Zealand vineyards}, journal = {Journal of Pest Science}, volume = {96}, year = {2023}, month = {JAN}, pages = {29-39}, type = {Article}, abstract = {

Mealybugs are phloem-feeding insects found on many crops worldwide. In New Zealand vineyards, they transmit the economically important Grapevine leafroll-associated virus 3 (GLRaV-3). For some mealybug species, synthetic sex pheromones have been commercialised, and are used as monitoring tools. The mealybugs Pseudococcus longispinus and Pseudococcus calceolariae are major pests in many New Zealand vineyards. We present work on the development of a combined P. longispinus and P. calceolariae pheromone lure. The optimal dose for monitoring P. longispinus was found to be 10 mu g of the (S)-(+)-enantiomer, either alone or in the racemic mixture. Addition of the corresponding alcohol did not improve trap catch of P. longispinus. Both the P. longispinus and the P. calceolariae pheromone lures remained active in the field for 90 days. Combining the 2 species{\textquoteright} pheromones had no negative effects on male mealybug trap catch for either species. We conclude that the pheromone ester alone is the best lure for the male P. longispinus. Combining the two mealybug species{\textquoteright} pheromones into a single lure provides the New Zealand viticultural industry with an efficient monitoring tool. Late-vintage deployment of baited lures will provide information on mealybug abundance and local distribution that will inform the scope of future insecticide programmes, to target areas based on need rather than an area-wide application by default.

}, keywords = {Citrophilus mealybug, Integrated pest management (IPM), Long-tailed mealybug, monitoring, Pseudococcus calceolariae, Pseudococcus longispinus}, issn = {1612-4758}, doi = {10.1007/s10340-022-01504-5}, author = {Sullivan, Nicola J. and Bell, Vaughn A. and Butler, Ruth C. and Wallis, Roger and Ramesh, Remya and Reddy, D. Srinivasa and Twidle, Andrew M. and Bunn, Barry and Unelius, C. Rikard and Manning, Lee-Anne M. and Suckling, David M.} } @article {48757, title = {Direct deoxygenation of α-hydroxy and α,β-dihydroxy ketones using a silyl lithium reagent}, journal = {Journal of Organic Chemistry}, volume = {88}, year = {2023}, month = {SEP}, pages = {14227-14235}, type = {Article}, abstract = {

A reliable method for the one-step direct deoxygenation of alpha-hydroxy ketones has been developed using a silyl lithium reagent and acetic anhydride. The method is metal-catalyst-free and does not require prefunctionalization of the hydroxy group prior to its removal. Deoxygenation of different primary, secondary, and tertiary alcohols was carried out with up to 98\% isolated yield. Additionally, double deoxygenation was achieved when the present method was applied to alpha,beta-dihydroxy ketones to access the corresponding enones in a single step.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.3c01613}, author = {Zade, Vishal M. and Gangnale, Laxmikant D. and Athawale, Paresh R. and Reddy, D. Srinivasa} } @article {48761, title = {Identification of new modulator of DNA repairing pathways based on natural product ({\textpm})-peharmaline A}, journal = {Bioorganic \& Medicinal Chemistry}, volume = {91}, year = {2023}, month = {AUG}, pages = {117365}, type = {Article}, abstract = {

The complex heterogenic environment of tumour mass often leads to drug resistance and facilitate chemo insensitivity triggering more malignant phenotypes among cancer patients. Major DNA-damaging cancer drugs have been consistently proven unsuccessful in terms of elevating chemo-resistance. (\& PLUSMN;)-peharmaline A, a hybrid natural product isolated from seeds of Peganum harmala L. possesses significant cytotoxic activities. Herein, we have described the design, and synthesis of a novel library of close and simplified analogues around the anticancer natural product (\& PLUSMN;)-peharmaline A and investigated their cytotoxic activities, which led to the identification of three structurally simplified lead compounds exhibiting better potency than parent natural product. Among them, demethoxy analogue of peharmaline A was further investigated for its anticancer potential eliciting demethoxy analogue as potent DNA-damage inducing agent attenuating the expression of the proteins responsible for the DNA damage repair. Therefore, this demethoxy analogue warrants detailed investigations for the confirmations of the molecular mechanism-based studies responsible for its anticancer activity.

}, keywords = {DNA damage, EMT, Pictet, Spengler reaction, Structure-activity relationship, Total synthesis}, issn = {0968-0896}, doi = {10.1016/j.bmc.2023.117365}, author = {Kulkarni, Akshay S. and Dash, Anshurekha and Shingare, Rahul D. and Chand, Jagdish and Manhas, Diksha and Singh, Aman and Nandi, Utpal and Goswami, Anindya and Reddy, D. Srinivasa} } @article {48764, title = {Scalable synthesis of silacyclohexanones and ready access to silicon building blocks}, journal = {Organic Letters}, volume = {25}, year = {2023}, month = {SEP }, pages = {6881-6885}, type = {Article}, abstract = {

A simple and efficient two-step method for the synthesis of silacyclohexanones starting from bis(bromoethylsilanes) using TosMIC is presented. The prepared silacyclohexanones were transformed to nine different heterocycles with silicon incorporation. In addition, the developed methodology was used for the synthesis of a sila analogue of the HDAC6 inhibitor tubastatin A.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.3c02561}, author = {Ramesh, Eagala and Nandawadekar, Laxman D. and Rao, Ramana Sreenivasa and Reddy, D. Srinivasa} } @article {48826, title = {Synthesis, biological evaluation and docking studies of silicon incorporated diarylpyrroles as MmpL3 inhibitors: an effective strategy towards development of potent anti-tubercular agents}, journal = {European Journal of Medicinal Chemistry}, volume = {259}, year = {2023}, month = {NOV }, pages = {115633}, type = {Article}, abstract = {

Growing global demand for new molecules to treat tuberculosis has created an urgent need to develop novel strategies to combat the menace. BM212 related compounds were found to be potent anti-TB agents and they inhibit mycolic acid transporter, MmpL3, a known potent drug target from Mycobacterium tuberculosis. In order to enhance their inhibitory potency, several silicon analogues of diarylpyrroles related to BM212 were designed, synthesized, and evaluated for anti-tubercular activities. In Alamar blue assay, most of the silicon-incorporated compounds were found to be more potent than the parent compound (BM212), against Mycobacterium tuberculosis (MIC = 1.7 \& mu;M, H37Rv). Docking results from the crystal structure of MmpL3 and silicon analogues as pharmacophore model also strongly correlate with the biological assays and suggest that the incorporation of silicon in the inhibitor scaffold could enhance their potency by stabilizing the hydrophobic residues at the binding pocket. The best docking hit, compound 12 showed an MIC of 0.1 \& mu;M against H37Rv with an acceptable in vitro ADME profile and excellent selectivity index. Overall, the present study indicates that, the designed silicon analogues, especially compound 12 could be a good inhibitor for an intrinsically flexible drug-binding pocket of MmpL3 and has potential for further development as anti-tubercular agents.

}, keywords = {antibiotic, BM212, docking studies, MmpL3 inhibitor, Silicon analogue, tuberculosis}, issn = {0223-5234}, doi = {10.1016/j.ejmech.2023.115633}, author = {Vasudevan, N. and Motiwala, Zenia and Ramesh, Remya and Wagh, Sachin B. and Shingare, Rahul D. and Katte, Revansiddha and Anand, Amitesh and Choudhary, Sushil and Kumar, Ajay and Gokhale, Rajesh S. and Kulkarni, Kiran A. and Reddy, D. Srinivasa} } @article {48801, title = {Total synthesis and absolute configuration determination of the α-glycosidase inhibitor (3S,4R)-6-Acetyl-3-hydroxy-2,2-dimethylchroman-4-yl (Z)-2-Methylbut-2-enoate from Ageratina grandifolia}, journal = {Journal of Natural Products}, volume = {86}, year = {2023}, month = {JUN}, pages = {1878-1883}, type = {Article}, abstract = {

Herein, we report the first total synthesis of \& alpha;-glycosidaseinhibitor (3R, 4S)-6-acetyl-3-hydroxy-2,2-dimethylchroman-4-yl(Z)-2-methylbut-2-enoate as well as its enantiomer.Our synthesis confirms the chromane structure separately proposedby Navarro-Vazquez and Mata, on the basis of DFT computations. Furthermore,our synthesis allowed us to determine the absolute configuration ofthe natural compound as (3S, 4R)and not (3R, 4S).

}, issn = {0163-3864}, doi = {10.1021/acs.jnatprod.3c00236}, author = {Dandawate, Monica and Choudhury, Rahul and Krishna, Gamidi Rama and Reddy, D. Srinivasa} } @article {49093, title = {Highly stereoselective diels-alder-based strategy for the synthesis of 3-epi-formicin A and 1-epi-formicin B}, journal = {Organic Letters}, volume = {26}, year = {2024}, month = {APR }, pages = {3961-3965}, type = {Article}, abstract = {

The first enantioselective approach based on a highly stereoselective Diels-Alder reaction for the synthesis of 3-epi-formicin A and 1-epi-formicin B with rare N-acetylcysteamine-containing indenone thioesters is reported. The strategy utilizes a key Diels-Alder reaction to form the core hydrindane system with three contiguous stereocenters in very high levels of diastereo- and regioselectivity and one-pot oxidation/isomerization/dehydrogenation. The scope of this method was tested with different substrates to give cycloadducts in a highly diastereoselective manner.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.4c01209}, author = {Khamkar, Sunil L. and Handore, Kishor L. and Shinde, Harish M. and Reddy, D. Srinivasa} } @article {49277, title = {Synthesis of benzofuran-6-carboxylic acid, an intermediate of lifitegrast with low-carbon footprints}, journal = {ACS SUSTAINABLE CHEMISTRY \& ENGINEERING}, volume = {12}, year = {2024}, month = {OCT}, pages = {15671-15681}, type = {Journal Article}, keywords = {benzofuran-6-carboxylicacid, dry eye disease, life cycle, lifitegrast, process development}, issn = {2168-0485}, doi = {10.1021/acssuschemeng.4c06361}, author = {Zade, Vishal M. and Athawale, Paresh R. and Kopperi, Harishankar and Mohan, S. Venkata and Reddy, D. Srinivasa} } @article {49082, title = {Total synthesis and revision of stereochemistry of a natural benzo[g]isochromene stereodiad isolated from rubia philippinensis}, journal = {Organic Letters}, volume = {26}, year = {2024}, month = {MAR }, pages = {2574-2579}, type = {Article}, abstract = {

This study presents a total synthesis and revision of the stereochemical configuration of the conformationally flexible natural product benzo[g]isochromene stereodiad alongside its diastereomeric counterparts. The highlights of the synthesis are the TiCl4-mediated diastereoselective aldol reaction, Pd-catalyzed lactonization, and Schmidt glycosidation. Our efforts using total synthesis disclosed herein proved that a previously assigned structure required revision.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.4c00553}, author = {Choudhury, Rahul and Miriyala, Satya Ravi Teja and Resmi, K. R. and Sridhar, Balasubramanian and Kasa, S. R. Krishna Murthy and Reddy, D. Srinivasa} } @article {49425, title = {Gram-scale synthesis of ({\textpm})-tylophorine}, journal = {Synlett}, volume = {36}, year = {2025}, month = {MAR}, pages = {536-540}, type = {Article}, abstract = {

We report a practical scalable synthesis of the natural product (+/-)-tylophorine by using an operationally simple protecting-group-free route from readily accessible starting materials. Synthesis of a cyclic N-acetyl diester compound through cyclization, followed by two key steps (decarboxylation and a Clemmensen reduction), provides access to the target molecule.

}, keywords = {alkaloids, Clemmensen reduction, decarboxylation, gram-scale synthesis, tylophorine}, issn = {0936-5214}, doi = {10.1055/a-2351-4828}, author = {Masal, Dattatraya P. and Reddy, D. Srinivasa} }