Synthesis of the tetrasaccharide lipid intermediate P1-dolichyl P2-[O-alpha-D-mannopyranosyl-(1----6)-O-beta-D-mannopyranosyl-(1----4) -O-(2- acetamido-2-deoxy-beta-D-glucopyranosyl)-(1----4)-2-acetamido-2- deoxy-alpha-D-glucopyranosyl] diphosphate.

O-alpha-D-Mannopyranosyl-(1----6)-O-beta-D-mannopyranosyl-(1----4)-O-(2- acetamido-2-deoxy-beta-D-glucopyranosyl)-(1----4)-2-acetamido-2-deoxy- D-glucopyranose was isolated from bovine or ovine mannosidosis urine. After peracetylation, treatment with trimethylsilyl trifluoromethanesulfonate gave a high yield of a peracetyl oxazoline, which was phosphorylated with dibenzyl phosphate to give a dibenzyl glycosyl phosphate that was converted into a peracetyl tetrasaccharide phosphate by catalytic hydrogenolysis. A coupling reaction with P1-dolichyl P2-diphenyl diphosphate, prepared in two stages from pig-liver dolichol, yielded a peracetyl diphosphoric diester, which on O-deacetylation gave P1-dolichyl P2-[O-alpha-D-mannopyranosyl-(1----6)-O-beta-D-mannopyranosyl-(1----4)-O -(2- acetamido-2-deoxy-beta-D-glucopyranosyl)-(1----4)-2-acetamido-2-deoxy- alpha-D- glucopyranosyl] diphosphate. This tetrasaccharide lipid intermediate was active as an acceptor of D-mannose residues from GDP-D-mannose in the presence of calf pancreas microsomes.