Synthesis of p-nitrophenyl 2-O-alpha-D-mannopyranosyl-alpha-D-mannopyranoside and p-nitrophenyl 6-O-alpha-D-mannopyranosyl-alpha-D-mannopyranoside.

Crystalline 2-O-alpha-D-mannopyranosyl-beta-D-mannopyranose octaacetate was synthesized by condensation of tetra-O-acetyl-alpha-D-mannopyranosyl bromide (3) with 1,3,4,6-tetra-O-acetyl-beta-D-mannopyranose. 6-O-alpha-D-Mannopyranosyl-alpha-D-mannopyranose octaacetate was prepared by condensation of 3 with 1,2,3,4-tetra-O-acetyl-6-O-trityl-alpha-D-mannopyranose. Fusion of each mannobiosyl octaacetate with p-nitrophenol was followed by deacetylation, to give the corresponding p-nitrophenyl (1 to 2) and (1 to 6)-alpha-D-mannobioside.