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-α-d-glucopyranoside derivatives by thiolate nucleophilic displacement of the 2-O-triflate of α-d-mannopyranoside derivatives were investigated. A synthesis of n-propyl 3,4,6-tri-O-benzyl-2-thio-β-d-glucopyranoside was developed. Glycosylation of this derivative with 2,3,4,6-tetra-O-acetyl-5-thio-α-d-glucopyranosyl trichloroacetimidate gave an α/β mixture of protected n-propyl β-dithiokojibioside and β-dithiosophoroside. Deprotection of the mixture by standard methods and separation by chromatography gave n-propyl β-dithiokojibioside (1) which is a potential enzyme inhibitor of glucosidase I.