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

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 (2S,3S)-diacetoxy-(1R,4R)-dihydroxycyclohex-5-ene, (−)-3, and (1S,2R,3R,4S)-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.     

Resolution of sclareolide as a key intermediate for the synthesis of Ambrox®

Sclareolide was efficiently resolved by a diastereomeric salt formation method using homochiral erythro-2-amino-1,2-diphenylethanol (ADPE) as a resolving agent.