Selective formation of C-2 azidodeoxy-D-glucose derivatives from D-glucal precursors using the azidonitration...

A series of glucals, protected by cyclic acetal protecting groups to conformationally constrain the C-4 and C-6 hydroxyl groups, were subjected to the azidonitration reaction to furnish the corresponding C-2 azidodeoxy-D-glucoses. 4,6-O-Isopropylidene-3-O-triisopropylsilyl-D-arabino-hex-1-enit ol afforded 2-azido-2-deoxy-4,6-O-isopropylidene-3-O-triisopropylsilyl-D-gluco pyranosyl nitrate and its D-manno isomer in a 20:1 ratio. These findings allow the azidonitration reaction to be now used for the preparation of a variety of glucosamine building blocks from differentially protected glucal precursors.