The synthesis of 3, 6-di-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-D-galactose, a branched trisaccharide reported as a hydrolysis product of blood-group substances.

Protected disaccharides were the only products that could be isolated after condensation of 3, 4, 6-tri-O-acetyl-2-deoxy-2-diphenoxyphosphoramido-alpha-D-glucopyranosyl bromide or 2-acetamido-3, 4, 6-tri-O-acetyl-2-deoxy-alpha-D-glucopyranosyl chloride with benzyl 2, 4-di-O-benzyl-beta-D-galactopyranoside. On the other hand, reaction of 2-methyl-(3, 4, 6-tri-O-acetyl-1, 2-dideoxy-alpha-D-glucopyrano)-[2', 1': 4, 5]-2-oxazoline (6 moles) with the same galactopyranoside (1 mole) gave benzyl 3, 6-di-O-(2-acetamido-3, 4, 6-tri-O-acetyl-beta-D-glucopyranosyl)-2, 4-di-O-benzyl-beta-D-galactopyranoside, which was converted, by alkaline methanolysis followed by hydrogenolysis, to the title compound. This appears identical with an oligosaccharide previously obtained through degredation of a blood-group A glycoprotein from hog gastric mucin.