Synthesis of Gal-beta-(1 -> 4)-GlcNAc-beta-(1 -> 6)-[Gal-beta-(1 -> 3)]-GalNAc-alpha-OBn oligosaccharides bearing O-methyl or O-sulfo groups at C-3 of the Gal residue: specific acceptors for Gal : 3-O-sulfotransferases

Our recent studies have revealed the existence of two distinct Gal: 3-O-sul fotransferases capable of acting on the C-3 position of galactose in a Core 2 branched structure, e.g,, Gal beta 1-->4GlcNAc beta-->G(Gal beta 1-->3)G alNac alpha 1-->OBenzyl as acceptor to give 3-O-sulfoGal beta 1-->4GlcNAc b eta 1-->3(Gal beta 1-->3)GalNAc alpha 1-->OB 20 and Gal beta 1-->4GlcNAc be ta 1-->6(3-O-sulfoGal beta 1-->3)GalNAc alpha 1-->OB 23. We herein report t he synthesis of these two compounds and also that of other modified analogs that are highly specific accepters for the two sulfotransferases, Appropri ately protected 1-thio-glycosides 7, 8, and 10 were employed as glycosyl do nors for the synthesis of our target compounds.