Synthesis of an antimetastatic tetrasaccharide β-d-Gal-(1 → 4)-β-d-GlcpNAc-(1 → 6)-α-d-Manp-(1 → 6)-β-d-Manp-OMe

An antimetastatic tetrasaccharide T1, β-d-Gal-(1 → 4)-β-d-GlcpNAc-(1 → 6)-α-d-Manp-(1 → 6)-β-d-Manp-OMe, was synthesized with two approaches. The first approach was a conventional method employing thioglycoside and Koenigs–Knorr glycosylation reaction in 24% overall yield. The second one was a novel route through the azidoiodo-glycosylation strategy by using 2-iodo-2-deoxylactosyl azide as the donor in 36% overall yield.