01496nas a2200169   4500008004100000022001400041245017400055210006900229260007100298300001400369490000700383520074000390100002101130700002601151700001901177856013001196       2006                        eng d  a0022-326300aFacile synthesis of 1,3,7-trihydroxyxanthone and its regioselective coupling reactions with prenal: simple and efficient access to osajaxanthone and nigrolineaxanthone F0 aFacile synthesis of 137trihydroxyxanthone and its regioselective  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUN  a4992-49950 v713 a<p>A facile five-step synthesis of naturally occurring 1,3,7-trihydroxyxanthone has been described starting from 1,3,5-trimethoxybenzene via NBS-induced nuclear bromination, lithiation followed by an in situ benzoylation with methyl 2,5-dibenzyloxybenzoate, selective deprotection of the two benzyl groups, base-catalyzed intramolecular cyclization, and demethylations pathway with 62% overall yield. The regioselective coupling reactions of 1,3,7-trihydroxyxanthone with prenal in the presence of calcium hydroxide at room temperature and under thermal conditions at 140-150 degrees C have been demonstrated to exclusively obtain the natural products osajaxanthone in 75% yield and nigrolineaxanthone F in 98% yield, respectively.</p>1 aMondal, Mukulesh1 aPuranik, Vedavati, G.1 aArgade, N., P.  uhttps://library.ncl.res.in/content/facile-synthesis-137-trihydroxyxanthone-and-its-regioselective-coupling-reactions-prenal-001430nas a2200169   4500008004100000022001400041245013600055210006900191260007100260300001400331490000700345520070500352100002601057700002601083700001901109856013201128       2007                        eng d  a0022-326300aFacile chemo-, regio-, and diastereoselective approach to cis-3,5-disubstituted gamma-butyrolactones and fused gamma-butyrolactones0 aFacile chemo regio and diastereoselective approach to cis35disub  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB  a1009-10120 v723 a<p>Chemoselective S(N)2' condensation of primary enolates of alkyl methyl ketones 2a-e with dimethyl bromomethylfumarate ( 1) followed by highly diastereoselective NaBH4 reduction of the ketone function in the formed ketodiesters 3a-e and the regioselective in situ lactonization of the unisolable intermediates 4a-e exclusively furnished the cis-3,5-disubstituted gamma-butyrolactones (+/-)-5a-e in very good yields. Similarly, the face-selective coupling reaction of cyclohexanone enolate with 1 to form a mixture of diastereomers in an 8: 2 ratio followed by a highly selective reductive cyclization of 9 plus 10 exclusively provided the cis-octahydrobenzofuran (+/-)- 12 in 70% overall yield.</p>1 aBaag, Md., Merajuddin1 aPuranik, Vedavati, G.1 aArgade, N., P.  uhttps://library.ncl.res.in/content/facile-chemo-regio-and-diastereoselective-approach-cis-35-disubstituted-gamma-butyrolactones01807nas a2200169   4500008004100000022001400041245019700055210006900252260007100321300001400392490000700406520103100413100002101444700002601465700001901491856012701510       2007                        eng d  a0022-326300aFacile phenol-driven intramolecular diastereoselective thermal/base-catalyzed dipolar [2+2] annulation reactions: an easy access to complex bioactive natural and unnatural benzopyran congeners0 aFacile phenoldriven intramolecular diastereoselective thermalbas  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR  a2068-20760 v723 a<p>The complex bioactive natural and unnatural benzopyran congeners have been synthesized using one-/two-step approaches in very good yields from the reactions of two different dihydroxyphthalides, natural resorcyclic acid derivative, and trihydroxybenzophenone with citral and/or farnesal, via the phenol-driven intramolecular diastereoselective thermal/base-catalyzed dipolar [2 + 2] cycloaddition reactions and three different thermal intramolecular cyclization reactions. The effects of the nature and the position of phenolic groups in the starting materials on the course of these cycloaddition reactions have also been described. Depending upon the absence or presence of intramolecular hydrogen bonding of the phenolic group with the carbonyl moiety in the starting materials, these phenol-driven intramolecular thermal/base-catalyzed dipolar [2 + 2] cycloaddition reactions either furnished the kinetically controlled products or directly formed the thermodynamically controlled rearranged products, respectively.</p>1 aMondal, Mukulesh1 aPuranik, Vedavati, G.1 aArgade, N., P.  uhttps://library.ncl.res.in/content/facile-phenol-driven-intramolecular-diastereoselective-thermalbase-catalyzed-dipolar-2201368nas a2200181   4500008004100000022001400041245011500055210006900170260010600239300001400345490000700359520059900366100002600965700002300991700002601014700001901040856012701059       2008                        eng d  a0040-402000aFacile air-oxidation of N-homopiperonyl-5,6-dimethoxyhomophthalimide: simple and efficient access to nuevamine0 aFacile airoxidation of Nhomopiperonyl56dimethoxyhomophthalimide   aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcFEB  a1786-17910 v643 a<p>A facile six-step synthesis of naturally occurring (+/-)-nuevamine with 55% overall yield has been described, starting from methyl 2-(6-formyl-2,3-dimethoxyphenyl)acetate via the quantitative benzylic air-oxidation of the corresponding N-homopiperonyl-5,6-dimethoxy-homophthalimide to N-homopiperonyl-5,6-dimethoxyisoquinoline-1,3,4-trione as the key reaction, followed by base catalyzed regioselective alcoholysis of the trione with ring contraction, acid catalyzed dehydrative ring closure of the formed lactamol and decarboxylation pathway. (C) 2007 Elsevier Ltd. All rights reserved.</p>1 aWakchaure, Prasad, B.1 aEaswar, Srinivasan1 aPuranik, Vedavati, G.1 aArgade, N., P.  uhttps://library.ncl.res.in/content/facile-air-oxidation-n-homopiperonyl-56-dimethoxyhomophthalimide-simple-and-efficient-001147nas a2200217   4500008004100000022001400041245013300055210006900188260010600257300001400363490000700377520025800384653002400642653001700666653002300683653001500706100002700721700002500748700002600773856013000799       2009                        eng d  a0040-403900aFirst ionic liquid-promoted Kabbe condensation reaction for an expeditious synthesis of privileged bis-spirochromanone scaffolds0 aFirst ionic liquidpromoted Kabbe condensation reaction for an ex  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJUN  a2643-26480 v503 a<p>A variety of privileged bis-spirochromanones were synthesized for the First time from 4,6-diacetyl resorcinol in one-pot by carrying out the Kabbe condensation in loom temperature ionic liquid [bbim]Br. (C) 2009 Elsevier Ltd. All rights reserved.</p>10aBis-spirochromanone10aIonic liquid10aKabbe condensation10aMorpholine1 aMuthukrishnan, Murugan1 aBasavanag, U., M. V.1 aPuranik, Vedavati, G.  uhttps://library.ncl.res.in/content/first-ionic-liquid-promoted-kabbe-condensation-reaction-expeditious-synthesis-privileged-002285nas a2200253   4500008004100000022001400041245013800055210006900193260007300262300001000335490000800345520134600353653001101699653001701710653001801727653002001745653002301765653002001788100002901808700002701837700002601864700002101890856012001911       2011                        eng d  a0022-286000aFacile synthesis of N-benzylated 3-alkyl-2,6-diarylpiperidin-4-ones: Stereochemical investigation by 1D/2D NMR and single-crystal XRD0 aFacile synthesis of Nbenzylated 3alkyl26diarylpiperidin4ones Ste  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR  a44-560 v9903 a<p>A series of thirteen 1-benzyl-3-alkyl-2,6-diarylpiperidin-4-ones 14-26 were conveniently synthesized in high yields 87-92%. In order to find the impact on piperidone stereochemistry, beside the N-benzylation, methyl/ethyl/isopropyl groups at C-3 and halo/alkyl/alkoxy/benzyloxy groups on the phenyl rings at C-2/C-6 were introduced. All the synthesized compounds were characterized by mass, (1)H and (13)C NMR spectral studies. Of them, the 1-benzyl-3-ethyl-2,6-diphenylpiperidin-4-one 22 was completely characterized by 2D NMR techniques such as (1)H-(1)H COSY, (1)H-(13)C COSY and NOESY to assign the signals, unambiguously. The proton coupling constants and NOE correlations provided the complete stereochemistry of 22, which is further witnessed by its single-crystal XRD analysis. The NMR and XRD studies revealed that the compound 22 exists in a chair conformation with equatorial orientation of all the substituents in both solution and solid states. On the basis of their vicinal coupling constants, the chair conformation with equatorial orientation of the substituents at C-2, C-3, C-6 and N is proposed for all compounds 14-26; moreover, a considerable population of boat conformation also suggested for the compound 26 along with the predominant chair conformation, in solution. (C) 2011 Elsevier B.V. All rights reserved.</p>10a2D NMR10aConformation10aN-benzylation10aPiperidin-4-one10asingle-crystal XRD10aStereochemistry1 aDindulkar, Someshwar, D.1 aParthiban, Paramasivam1 aPuranik, Vedavati, G.1 aJeong, Yeon, Tae  uhttps://library.ncl.res.in/content/facile-synthesis-n-benzylated-3-alkyl-26-diarylpiperidin-4-ones-stereochemical-001540nas a2200193   4500008004100000022001400041245007900055210006900134260011000203300001400313490000600327520079100333100001801124700002601142700001801168700001901186700002801205856011301233       2011                        eng d  a1744-683X00aFerrocene based organometallic gelators: a supramolecular synthon approach0 aFerrocene based organometallic gelators a supramolecular synthon  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB  a3634-36410 v73 a<p>The supramolecular synthon namely primary ammonium dicarboxylate (PAD) synthon has been exploited to generate a new series of salt based low molecular weight gelators (LMWGs) derived from ferrocenedicarboxylic acid (FDCA) and primary amines Me-(CH2)(n)-NH2 (n = 3-15). While most of the salts are capable of forming gels with DMSO and DMF, nearly all of them show a tendency to form gels with at least one of the solvents studied. Structure property correlation based on single crystal and powder X-ray diffraction data in combination with optical-, scanning-, and transmission-electron microscopy reveals that the supramolecular synthon approach adopted herein for designing LMWGs is indeed useful and allows one to get an easy access to a new series of organometallic gelators.</p>1 aSahoo, Pathik1 aPuranik, Vedavati, G.1 aPatra, A., K.1 aSastry, P., U.1 aDastidar, Parthasarathi  uhttps://library.ncl.res.in/content/ferrocene-based-organometallic-gelators-supramolecular-synthon-approach-001412nas a2200253   4500008004100000022001400041245011200055210006900167260007500236300001400311520049400325653001600819653002000835653001900855653001400874653001400888100002400902700001800926700002600944700002100970700002700991700001901018856012101037       2011                        eng d  a0039-788100aFirst total synthesis of 5-hydroxy-3-methyl-4-propylsulfanyl-5H-furan-2-one: a cancer chemopreventive agent0 aFirst total synthesis of 5hydroxy3methyl4propylsulfanyl5Hfuran2o  aRUDIGERSTR 14, D-70469 STUTTGART, GERMANYbGEORG THIEME VERLAG KGcMAY  a1595-15983 a<p>The first total synthesis of 5-hydroxy-3-methyl-4-propylsulfanyl-5H-furan-2-one, a newly discovered natural product with anticancer property is described by two different routes. A sequence involving an incorporation of a methyl group via a Gilman reagent and a chemoselective reduction of a cyclic anhydride functionality are the key steps. The methods proposed start from easily available starting materials and allow ready preparation of the final compound in good overall yield.</p>10aAllium cepa10achemopreventive10aGilman reagent10aselective10asynthesis1 aBorikar, Sanjay, P.1 aPaul, Vincent1 aPuranik, Vedavati, G.1 aSathe, Vilas, T.1 aLagunas-Rivera, Selene1 aOrdonez, Mario  uhttps://library.ncl.res.in/content/first-total-synthesis-5-hydroxy-3-methyl-4-propylsulfanyl-5h-furan-2-one-cancer-001149nas a2200241   4500008004100000022001400041245007500055210006900130260010600199300001400305490000700319520028300326653001500609653002200624653002200646653002800668653001500696100002400711700002300735700002600758700002300784856010000807       2012                        eng d  a0040-403900aFormal synthesis of (-)-stemoamide using a useful epimerization at C-80 aFormal synthesis of stemoamide using a useful epimerization at C  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAY  a2647-26500 v533 a<p>The formal synthesis of (-)-stemoamide was achieved starting from L-pyroglutamic acid. The key steps used are the allylation using BF3 center dot OEt2, ring closing metathesis, allylic oxidation and a novel epimerization at C8. (C) 2012 Elsevier Ltd. All rights reserved.</p>10aAllylation10aAllylic oxidation10aPyroglutamic acid10aRing closing metathesis10aStemoamide1 aChavan, Subhash, P.1 aHarale, Kishor, R.1 aPuranik, Vedavati, G.1 aGawade, Rupesh, L.  uhttps://library.ncl.res.in/content/formal-synthesis-stemoamide-using-useful-epimerization-c-8-001408nas a2200217   4500008004100000022001400041245012300055210006900178260011000247300001200357490000700369520051400376100002100890700002200911700002400933700002300957700002600980700003501006700002801041856012101069       2014                        eng d  a1477-052000aFormation of a pseudo-beta-hairpin motif utilizing the Ant-Pro reverse turn: consequences of stereochemical reordering0 aFormation of a pseudobetahairpin motif utilizing the AntPro reve  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB  a774-7820 v123 a<p>Herein, we report a special case of pseudo-beta-hairpin formation by tetrapetide sequences featuring a two-membered Ant Pro dipeptide motif (Ant = anthranilic acid and Pro = proline) at the loop region. These folded structures uniquely feature the presence of C9- and C17-H-bonding patterns at reverse turn and interstrand regions, respectively. Their hairpin nucleation and folding propensities have been expounded using solution and solid state studies of distinct stereochemically altered sequences.</p>1 aNair, Roshna, V.1 aKotmale, Amol, S.1 aDhokale, Snehal, A.1 aGawade, Rupesh, L.1 aPuranik, Vedavati, G.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/formation-pseudo-beta-hairpin-motif-utilizing-ant-pro-reverse-turn-consequences-002215nas a2200277   4500008004100000022001400041245010800055210006900163260007300232300001000305490000900315520124800324653001301572653000801585653002101593653002301614653001401637653001501651100002101666700002401687700002201711700002301733700002601756700002701782856012801809       2015                        eng d  a0022-286000aFirst naphthosemiquinone complex of K+ with vitamin K3 analog: experiment and density functional theory0 aFirst naphthosemiquinone complex of K with vitamin K3 analog exp  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY  a56-630 v10883 a<p>Synthesis and characterization of potassium complex of 2-hydroxy-3-methyl-1,4-naphthoquinone (phthiocol), the vitamin K3 analog, has been carried out using FT-IR, UV-Vis, H-1 and C-13 NMR, EPR, cyclic voltammetry and single crystal X-ray diffraction experiments combined with the density functional theory. It has been observed that naphthosemiquinone binds to two K+ ions extending the polymeric chain through bridging oxygens O(2) and O(3). The crystal network possesses hydrogen bonding interactions from coordinated water molecules showing water channels along the c-axis. C-13 NMR spectra revealed that the complexation of phthiocol with potassium ion engenders deshielding of C(2) signals, which appear at delta = similar to 14.6 ppm whereas those of C(3) exhibit up-field signals near delta similar to 6.9 ppm. These inferences are supported by the M06-2x based density functional theory. Electrochemical experiments further suggest that reduction of naphthosemiquinone results in only a cathodic peak from catechol. A triplet state arising from interactions between neighboring phthiocol anion lead to a half field signal at g = 4.1 in the polycrystalline X-band EPR spectra at 133 K. (C) 2015 Elsevier B.V. All rights reserved.</p>10aC-13 NMR10aDFT10ahydrogen bonding10aNaphthosemiquinone10aPhthiocol10aVitamin K31 aKathawate, Laxmi1 aGejji, Shridhar, P.1 aYeole, Sachin, D.1 aVerma, Prakash, L.1 aPuranik, Vedavati, G.1 aSalunke-Gawali, Sunita  uhttps://library.ncl.res.in/content/first-naphthosemiquinone-complex-k-vitamin-k3-analog-experiment-and-density-functional-0