Synthesis of 2,3-di-O-glycosyl derivatives of methyl alpha- and beta-D-glucopyranoside.

The syntheses are described of 2,3-di-O-glycosyl derivatives of methyl alpha- and beta-D-glucopyranoside having alpha-D-manno-, beta-D-galacto-, alpha-L-rhamno-, alpha-L-fuco-, and beta-L-fuco-pyranosyl substituents at O-2 and O-3. The syntheses involved glycosylation of methyl 4,6-O-benzylidene-alpha- (24) and -beta-D-glucopyranoside (21), and substituted derivatives of 21 bearing 2-O-(2,3,4,6-tetra-O-benzoyl-alpha-D-mannopyranosyl)-, -(2,3,4,6-tetra-O- acetyl-beta-D-galactopyranosyl)-, -(2,3,4,-tri-O-benzoyl-alpha-L- rhamnopyranosyl)-, and -(2,3,4-tri-O-benzoyl-beta-L-fucopyranosyl) groups.