Synthetic Studies on (+)-Biotin, Part 15: A Chiral Squaramide-Mediated Enantioselective Alcoholysis Approach toward the Total Synthesis of (+)-Biotin

Xu-Xiang Chen, Fei Xiong, Han Fu, Zhi-Qian Liu, Fen-Er Chen
2011 Chemical and pharmaceutical bulletin  
Over the past two decades, significant progress in organocatalysis has been achieved by mark advances in the enantioselective desymmetrization of meso and other prochiral compounds. Well known in the respect is the catalytic asymmetric desymmetrization of meso-cyclic anhydride via the addition of an alcohol nuclophile, which represents a simple and elegant method for the preparation of synthetically pliable hemiester with the generation of either single or multiple stereocenters with high
more » ... ers with high levels of enantiocontrol in one symmetry-breaking operation. 2-13) While naturally-occurring cinchona alkaloids such as quinine, quinidine and their variants have been demonstrated to serve as practical organocatalysts for the enantioselective alcoholysis of fiveand six-membered meso-cyclic anhydrides since the pioneering works by Oda and colleagues 14, 15) in the late 1980s.
doi:10.1248/cpb.59.488 pmid:21467680 fatcat:w7pyqjkz2zgmxgkbh4psrnp72y