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

A series of glucals, protected by cyclic acetal protecting groups to confor mationally constrain the C-4 and C-6 hydroxyl groups, were subjected to the azidonitration reaction to furnish the corresponding C-2 azidodeoxy-D-gluc oses. 4,6-O-Isopropylidene-3-O-triisopropylsilyl-D-arabino-hex-1-enitol aff orded 2-azido-2-deoxy-4,6-O-isopropylidene-3-O-triisopropylsilyl-D-glucopyr anosyl 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 variet y of glucosamine building blocks from differentially protected glucal precu rsors. (C) 2000 Elsevier Science Ltd. All rights reserved.