R. I. El-Sokkary, R. Bassily, R. H. Youssef
Mar 1, 1998
Citations
0
Influential Citations
5
Citations
Journal
Journal of Carbohydrate Chemistry
Abstract
Abstract A tetrasaccharide glycoside comprising the core of the sialyl Lewis X structure was synthesized from “building-block” derivatives of the component sugar units. Initially 2-methyl-(3,4,6-tri-O-acetyl-1,2-dideoxy-α-D-glucopyrano)-[2′,1′:4,5]-2-oxazoline (1) was coupled to the known 2-(trimethylsilyl) ethyl 2,3,6,2′,4′,6′-hexa-O-benzyl-β-D-lactoside to give a trisaccharide glycoside (3) in 60% yield. De-O-acetylation, benzylidenation, benzylation, and reductive opening of the benzylidene acetal function of 6 gave a derivative having OH-4′ open. This derivative was coupled with tetra-O-acetyl-α-D-galactosyl bromide to give a tetrasaccharide in 62% yield, and the product was de-O-acetylated and de-O-benzylated to give the target compound, 2-(trimethylsilyl) ethyl β-D-galactopyranosyl-(1→4)-2-acetamido-2-deoxy-β-D-glucopyranosyl-(1→3)-β-D-galactopyranosyl-(1→4)-β-D-glucopyranoside (11).