Synthesis of Hexp-(1 → 4)-β-d-GlcpNac-(1 → 2)-α-d-Manp-(1 → O)(CH2)7CH3 probes for exploration of the substrate specificity of glycosyltransferases: Part II, Hex = 3-O-methyl-β-d-Gal, 3-deoxy-β-d-Gal, 3-deoxy-3-fluoro-β-d-Gal, 3-amino-3-deoxy-β-d-Gal, β-d

Seven analogues of the trisaccharide β-d-Galp-(1 → 4)-β-d-GlcpNAc-(1 → 2)-α-d-Manp-(1 → O)(CH2)7CH3 have been synthesized as potential substrates for glycosyltransferases involved in the chain-termination of N-acetyllactosamine-type N-glycans. These compounds include: 3-O-methyl-β-d-Galp-(1 → 4)-β-d-GlcpNAc-(1 → 2)-α-d-Manp-(1 → O)(CH2)7CH3, 3-deoxy-β-d-Galp-(1 → 4)-β-d-GlcpNAc-(1 → 2)-α-d-Manp-(1 → O)(CH2)7CH3, 3-deoxy-3-fluoro-β-d-Galp-(1 → 4)-β-d-GlcpNAc-(1 → 2)-α-d-Manp-(1 → O)(CH2)7CH3, 3-amino-3-deoxy-β-d-Galp-(1 → 4)-β-d-GlcpNAc-(1 → 2)-α-d-Manp-(1 → O)(CH2)7CH3, β-d-Gulp-(1 → 4)-β-d-GlcpNAc-(1 → 2)-α-d-Manp-(1 → O)(CH2)7CH3, β-l-Galp-(1 → 4)-β-d-GlcpNAc-(1 → 2)-α-d-Manp-(1 → O)(CH2)7CH3, and α-l-Altp-(1 → 4)-β-d-GlcpNAc-(1 → 2)-α-d-Manp-(1 → O)(CH2)7CH3. All trisaccharides were obtained by condensation of suitably modified glycosyl donors based on imidates or thioglycosides with the same disaccharide acceptor, octyl 3,4,6-tri-O-benzyl-2-O-(3,6-di-O-benzyl-2-deoxy-2-phthalimido-β-d-glucopyranosyl) -α-d-mannopyranoside, followed by deprotection. © 1997 Elsevier Science Ltd.