Synthesis of a dithio analogue of n-propyl kojibioside as a potential glucosidase I inhibitor

Procedures for the preparation of 3,4,6-protected 2-thio-alpha-D-glucopyranoside derivatives by thiolate nucleophilic displacement of the 2-O-triflate of alpha-D-mannopyranoside derivatives were investigated. A synthesis of n-propyl 3,4,6-tri-O-benzyl-2-thio-beta-D-glucopyran was developed. Glycosylation of this derivative with 2,3,4,6-tetra-O-acetyl-5-thio-alpha-D -glucopyranosyl trichloro-acetimidate gave an alpha/beta mixture of protected n-propyl beta-dithiokojibioside and beta-dithiosophoroside. Deprotection of the mixture by standard methods and separation by chromatography gave n-propyl beta-dithiokojibioside (1) which is a potential enzyme inhibitor of glucosidase I. (C) 1998 Elsevier Science Ltd. All rights reserved.