Synthetic mucin fragments: synthesis of O-sulfo and O-methyl derivatives of allyl [formula omitted] as potential compounds for sulfotransferases

Abstract

Allyl 2- acetamido-4,6-O-(4- methoxybenzylidene)-2- deoxy-α- d-galactopyranoside ( 1) was condensed with either 2,3,4,6- tetra-O- acetyl-α- d-galactopyranosyl bromide ( 2) or 2,3,4- tri-O- benzoyl6-O- bromoacetyl-α- d-galactopyranosyl bromide ( 14) in the presence of mercuric cyanide. Selective substitution with methyl, sulfo or both at desired positions, followed by the removal of protecting groups, afforded allyl O-(β d-galactopyranosyl )-(1 → 3)-2- acetamido-2-deoxy-6-O- methyl-α- d-galactopyranoside ( 5), allyl O-(6-O- sulfo-α- d-galactopyranosyl sodium salt)-(1 → 3)-2-acetamido-2-deoxy -6-O- methyl-α- d-galactopyranoside ( 10), allyl O-(β- d-galactopyranosyl)-(1 → 3)-2-acetamido-2-deoxy -6-O- sulfo-α- d-galactopyranoside sodium salt ( 13), allyl O-(6-O- sulfo-β- d-galactopyranosyl sodium salt)-(1 → 3)-2-acetamido-2-deoxy -α- d-galactopyranoside ( 17) and allyl O-(3-O- sulfo-β- d-galactopyranosyl sodium salt)-(1 → 3)-2-acetamido-2-deoxy -α- d-galactopyranoside ( 22). The structures of compounds 5, 10, 13, 17 and 22 were established by 13C NMR and FAB mass spectroscopy.