Glucosamine derivative 4 is a widely used precursor for syntheses of glucosamine-containing building blocks. A wide range of O-, S- and N-glycosides can be obtained from 4 under Lewis acid catalysis using the corresponding alcohols, thiols, or nitrogenous bases as nucleophiles. Since α-anomer of 4 shows much lower reactivity under these conditions, the use of pure β-anomer of 4 rather than anomeric mixture is preferred. Compound 4 is also a versatile substrate for generating the corresponding glycosyl halides under mild conditions.
