@article {45947, title = {Chirality induction and chiron approaches to enantioselective total synthesis of alpha-lipoic acid}, journal = {Tetrahedron}, volume = {71}, year = {2015}, month = {JUN }, pages = {4213-4218}, type = {Article}, abstract = {

An efficient, short and convenient asymmetric synthesis of (R)-(+)-lipoic acid in seven steps from chiral hydroxy aldehyde with 32.5\% overall yield is described. Synthesis of S and R enantiomers of a-lipoic acid from cis-1,4-butene diol derived chiral lactone is reported with 34 \% overall yield. The present synthesis involves use of simple reaction conditions making it a convenient synthesis. (C) 2015 Elsevier Ltd. All rights reserved.

}, keywords = {Chiral pool, Chirality induction, enantioselective, Lipoic acid, sharpless asymmetric dihydroxylation}, issn = {0040-4020}, doi = {10.1016/j.tet.2015.04.090}, author = {Chavan, Subhash P. and Pawar, Kailash P. and Praveen, Ch and Patil, Niteen B.} } @article { ISI:000352671600006, title = {Total synthesis of (R)-lipoic acid and (S)-lipoic acid via an Mn (III)-salen-catalyzed oxidative kinetic resolution}, journal = {Tetrahedron-Asymmetry}, volume = {26}, number = {5-6}, year = {2015}, month = {MAR}, pages = {281-287}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

The asymmetric synthesis of both the antipodes of alpha-lipoic acid is described. The total synthesis of racemic and asymmetric lipoic acid is achieved from propane 1,3-diol. This work reports the use of Mn (III)-salen-catalyzed oxidative kinetic resolution as the key step to obtain enantiomerically pure (R)- and (S)-lipoic acid. The undesired product formed during the resolution can be recycled to achieve the desired isomer. (C) 2015 Elsevier Ltd. All rights reserved.

}, issn = {0957-4166}, doi = {10.1016/j.tetasy.2015.02.001}, author = {Purude, Abhijeet N. and Pawar, Kailash P. and Patil, Niteen B. and Kalkote, Uttam R. and Chavan, Subhash P.} } @article {46634, title = {Scalable synthesis of 3-Ethyl-4-methyl-1,5-dihydro-2H-pyrrol-2-one: an important building block of the antidiabetic drug glimepiride}, journal = {Synthesis-Stuttgart}, volume = {52}, year = {2020}, month = {NOV}, pages = {3480-3484}, type = {Article}, abstract = {

A four-step, practical, and easily scalable synthesis of 3-ethyl-4-methyl-1,5-dihydro-2H-pyrrol-2-one, an important building block of the antidiabetic drug glimepiride, has been accomplished. Key features are the synthesis of 3-methyl-4-hydroxy-2-butenolide in water and triflic acid mediated N-benzyl lactam N-deprotection. The main advantages of this process are the scalable synthetic route and decreased number of reaction steps, which paves the way for the industrial-scale synthesis of 3-ethyl-4-methyl-1,5-dihydro-2H-pyrrol-2-one.

}, keywords = {antidiabetic drug, Butenolide, glimepiride, lactams, scalable synthesis}, issn = {0039-7881}, doi = {10.1055/s-0040-1707344}, author = {Chavan, Subhash P. and Pawar, Ambaji A. and Patil, Niteen B. and Kadam, Appasaheb L. and Shinde, Shrikrishna S.} } @article {47349, title = {Application of allylic amine formation from aziridine-2-ol under appel reaction condition: synthesis of N-(tert-butoxycarbonyl)-D-vinyl glycine methyl ester}, journal = {Tetrahedron Letters}, volume = {73}, year = {2021}, month = {JUN }, pages = {153119}, type = {Article}, abstract = {

PPh3/I-2/imidazolde mediated allyl amine formation from aziridine-2-alcohol was explored for the synthesis of N-(tert-butoxycarbonyl)-D-vinyl glycine methyl ester. (C) 2021 Published by Elsevier Ltd.

}, keywords = {Allyl amine, Aziridine-2-alcohol, Aziridinium ion, Birch reaction, Ring opening}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2021.153119}, author = {Chavan, Subhash P. and Kawale, Sanket A. and Patil, Niteen B. and Kalbhor, Dinesh B.} } @article {47615, title = {Multi-step synthesis of miltefosine: integration of flow chemistry with continuous mechanochemistry}, journal = {Chemistry-A European Journal}, volume = {27}, year = {2021}, month = {DEC }, pages = {17695-17699}, type = {Article}, abstract = {Herein we report for the first time, an advanced continuous flow synthesis of the blockbuster Leishmaniasis drug miltefosine from simple starting materials by a sequence involving four steps of chemical transformation including a continuous mechanochemical step. First three reaction steps were performed in simple tubular reactors in a telescopic mode, while in the last step the product precipitated from the 3(rd) step was used for a continuous mechanochemical synthesis of miltefosine. When compared to a typical batch protocol that takes 15 h, miltefosine was obtained in 58 \% overall yield in flow synthesis mode at the laboratory scale in a total residence time 34 min at synthesis rate of 10 g/hr, which is sufficient to treat 4800 patients per day.}, keywords = {continuous flow, continuous mechanochemistry, miltefosine, multistep synthesis, reactive intermediates}, issn = {0947-6539}, doi = {10.1002/chem.202103499}, author = {Patil, Niteen B. and Atapalkar, Ranjit S. and Chavan, Subhash P. and Kulkarni, Amol A.} }