Facile Preparation of 1,6-Anhydro-2-azido-3-O-benzyl-2-deoxy-β-D-glucopyranose and Its 4-O-Substituted Derivatives
Treatment of 1,6-anhydro-2,3-O-endo-benzylidene-β-D-mannopyranose derivatives with trimethylamine-borane (1/1)-aluminium chloride resulted in highly regioselective fission of the cyclic acetals to give the corresponding 2-O-unprotected-3-O-benzyl derivatives. Trifluoromethane-sulfonylation of these, followed by nucleophilic substitution, afforded 2-azido-2-deoxy derivatives in good yields.