Acetolysis of methyl 3- O-(2-acetamido-3,4,6-tri- O-acetyl-2-deoxy-β- d-glucopyranosyl)-2,4,6-tri- O-acetyl-α- d-galactopyranoside afforded 3- O-(2-acetamido-3,4,6-tri- O-acetyl-2-deoxy-β- d-glucopyranosyl)-1,2,4,6-tetra- O-acetyl- d-galactopyranose ( 2). Treatment of 2 in dichloromethane with hydrogen bromide in glacial acetic acid gave 3- O-(2-acetamido-3,4,6-tri- O-acetyl-2-deoxy-β- d-glucopyranosyl)- 2,4,6-tri- O-acetyl-α- d-galactopyranosyl bromide ( 3). The α configuration of 3 was indicated by its high, positive, specific rotation, and supported by its 1H-n.m.r. spectrum. Reaction of 3 with Amberlyst A-26- p-nitrophenoxide resin in 1:4 dichloromethane-2-propanol furnished p-nitrophenyl 3- O-(2-acetamido-3,4,6- tri- O-acetyl-2-deoxy-β- d-glucopyranosyl)-2,4,6-tri- O-acetyl-β- d-galactopyranoside ( 7). Compound 7 was also obtained by the condensation (catalyzed by silver trifluoromethanesulfonate-2,4,6-trimethylpyridine) of 3,4,6-tri- O-acetyl-2-deoxy-2-phthalimido-β- d-glucopyranosyl bromide with p-nitrophenyl 2,4,6-tri- O-acetyl-β- d-galactopyranoside, followed by the usual deacylation-peracetylation procedure. O-Deacetylation of 7 in methanolic sodium methoxide furnished the title disaccharide ( 8). The structure of 8 was established by 13C-n.m.r. spectroscopy.