Methyl 3, 4, 6-tri- O-benzyl-β- d-mannopyranoside ( 2), methyl 2, 3- O-isopropylidene-β- d-mannopyranoside ( 11), and 4-nitrophenyl 2, 3- O-isopropylidene-β- d-mannopyranoside ( 12) were each condensed with 2, 3, 4, 6-tetra- O-acetyl-α- d-mannopyranosyl bromide ( 1) in the presence of mercuric cyanide, to give after deprotection, methyl 2- ( 5) and 6- O-α- d-mannopyranosyl-β- d-mannopyranoside ( 15), and 4-nitrophenyl 6- O-α- d-mannopyranosyl-β- d-mannopyranoside ( 20), respectively. A similar condensation of 11 with 3, 4, 6-tri- O-acetyl-2- O-(2, 3, 4, 6-tetra- O-acetyl-α- d-mannopyranosyl)-α- d-mannopyranosyl bromide ( 21) and 2, 3, 4-tri- O-acetyl-6- O-(2, 3, 4, 6-tetra- O-acetyl-α- d-mannopyranosyl)-α- d-mannopyranosyl bromide ( 25), followed by removal of protecting groups, afforded methyl O-α- d-mannopyranosyl-(1 → 2)- O-α- d-mannopyranosyl-(1 → 6)-β- d-mannopyranoside ( 24) and methyl O-α- d-mannopyranosyl-(1 → 6)- O-α- d-mannopyranosyl-(1 → 6)-β- d-mannopyranoside ( 28), respectively. Bromide 25 was also condensed with 12 to give a trisaccharide derivative which was deprotected to furnish 4-nitrophenyl O-α- d-mannopyranosyl-(1 → 6)-α- d-mannopyranosyl-(1 → 6)-β- d-mannopyranoside ( 31). Phosphorylation of methyl 3, 4, 6-tri- O-benzyl-2- O-α- d-mannopyranosyl-β- d-mannopyranoside and 15 with diphenyl phosphorochloridate in pyridine gave the 6′-phosphates 6 and 16, respectively. Hydrogenolysis of the benzyl and phenyl groups provided methyl 2- O-(disodium α- d-mannopyranosyl 6-phosphate)-β- d-mannopyranoside ( 7) and methyl 6- O-(disodium α- d-mannopyranosyl 6-phosphate)-β- d-mannopyranoside ( 17) after treatment with Amberlite IR-120 (Na +) cation-exchange resin. The structures of compounds 5, 7, 15, 17, 20, 24, 28, and 31 were established by 13C-n.m.r. spectroscopy.