@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: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 {44462, title = {Efforts to access the potent antitrypanosomal marine natural product janadolide: synthesis of des- tert -butyl janadolide and its biological evaluation}, journal = {ACS Omega}, year = {2018}, month = {FEB}, abstract = {To identify novel antitrypanosomal agents based on Janadolide, a potent macrocyclic polyketide{\textendash}peptide hybrid, a macrolactonization strategy was explored. We prepared des-tert-butyl Janadolide and evaluated its antitrypanosomal activity. Our findings suggest that the tert-butyl group is necessary for the desired bioactivity.}, doi = {10.1021/acsomega.7b01920}, author = {Athawale, Paresh R. and Jachak, Gorakh and Shukla, Anurag and Shanmugam, Dhanasekaran and Reddy, 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 {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 {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 {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 {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 {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} }