Enzymatic resolution of (±)-conduritol-B, a key intermediate for the synthesis of glycosidase inhibitors

Abstract

Lipases from porcine pancreas, Candida cylindracea and Mucor miehei (adsorbed on support, Lipozyme ® IM) catalysed in t-butylmethylether the alcoholysis of rac-conduritol-B peracetate, (±)- 1, by n-butanol to give enantiopure (2 S,3 S)-diacetoxy-(1 R,4 R)-dihydroxycyclohex-5-ene, (−)- 3, and (1 S,2 R,3 R,4 S)-tetraacetoxy-cyclohex-5-ene, (+)- 1. The enantioforms (+)- and (−)-conduritol-B, obtained after chemical hydrolysis of (−)- 3 and (+)- 1, respectively, may be employed to prepare both the enantiomers of conduritol-B epoxide and cyclophellitol, powerful inhibitors of glycosidases.