Highly efficient synthesis of two Globo H tetrasaccharide analogues

The synthesis of two Globo H tetrasaccharide analogues, allyl O-(β-D-glucopyranosyluronic acid)-(1, 3)-O-(β-D-galactopyranosyl)-(1, 3)-(2-acetamido-2-deoxy-β-D-galactopyranosyl)-(1, 3)-O-α-D-galactopyranoside and allyl O-(3-O-sulfo-β-D-glucopyranosyluronic acid)-(1, 3)-O-(β-D-galactopyranosyl)-(1, 3)-(2-acetamido-2-deoxy-β-D-galactopyranosyl)-(1, 3)-O-α-D-galactopyranoside, were described. Construction of the target molecules was achieved through a key combination of BF ₃·Et ₂O and trichloroacetimidate glycosylation methodology. This is the first report on the synthesis of these derivatives, which could be used as potential novel substrates and reference samples for the study of β1, 3-glucuronosyltransferase and GlcA-3-O-sulfotransferase in cancer tissues.