Nitrogen-containing carbohydrate derivatives. Part XXX. Preparation and reactions of methyl 4,6-O-benzylidene-2,3-dideoxy-2,3-epimino-D-gulo- and -D-talopyranosides

Abstract

Methyl 4,6-O-benzylidene-α- and β-galactopyranosides have been converted into the α- and β-anhydro-gulosides and -talosides, which in turn have been subjected to azidolysis conditions. The major products were azidoidosides, but minor products were isolated in some cases and their structures were investigated. The azidoidosides were sulphonylated and treated with lithium aluminium hydride to give the title compounds (α- and β-gulo- and β-talo-). Deamination of the epimines gave 2,3-unsaturated sugars. Azidolysis of the α-talo-epimine and subsequent reactions gave methyl 2,3-acetamido-4,6-O-benzylidene-2,3-dideoxy-α-D-idopyranoside.