Synthesis of 4-Nitrophenyl 2-Acetamido-2-deoxy-β-D-mannopyranoside and 4-Nitrophenyl 2-Acetamido-2-deoxy-α-D-mannopyranoside

The title compounds were synthesized by the selective reduction of the azido group in 4-nitrophenyl 3,4,6-tri-O-acetyl-2-azido-2-deoxy-α-D-mannopyranoside (8) and 4-nitrophenyl 3,4,6-tri-O-acetyl-2-azido-2-deoxy-β-D-mannopyranoside (11), and by subsequent acetylation. Compound8was prepared by opening of the epoxide ring in methyl 2,3-anhydro-4,6-O-benzylidene-α-D-glucopyranoside (1) with sodium azide, followed by inversion of the configuration at C-3 in the resulting altropyranoside and glycosidation with 4-nitrophenol.