The nitrous acid deamination of glycosides and acetates of 2-amino-2-deoxy-D-glucose

A procedure is described for the nitrous acid deamination of 2-amino-2-deoxy-D-glucose hydrochloride (1), and reduction of the product with buffered borohydride, to afford crystalline 2,5-anhydro-D-mannitol (3) in 71% yield. Similar treatment of the methyl α-pyranoside (4) of 1 gives 59% of crystalline 3, and the same product is obtained in 44% yield from 1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy-α(or β)-D-glucopyranose hydrochloride (5 or 6) by the deamination-reduction sequence with subsequent deacetylation. These results provide a model, for a nonhydrolytic, depolymerization technique for structural characterization of glycosaminoglycans.