Synthesis of chondroitin sulfate E hexasaccharide in the repeating region by an effective elongation strategy toward longer chondroitin oligosaccharide

Abstract

We synthesized chondroitin and its sulfate E hexasaccharides (1 and 2) composed of the trimer of the repeating disaccharide, β-D-GalNAc(±4, 6-di-O-SO3Na)-(1→4)-β-D-GlcA, by employing an efficient synthetic strategy for longer chondroitin oligosaccharide. Successful elongation with the β-D-GalNAc-(1→4)-β-D-GlcA unit instead of the corresponding disaccharide possessing an azide group avoided problematic reduction of the multiple azide groups on the hexasaccharide.