Selective formation of C-2 azidodeoxy-d-glucose derivatives from d-glucal precursors using the azidonitration reaction

Abstract 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-enitol afforded 2-azido-2-deoxy-4,6- O -isopropylidene-3- O -triisopropylsilyl- d -glucopyranosyl 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.