Synthesis of hyaluronic-acid-related oligosaccharides and analogues, as their 4-methoxyphenyl glycosides, having N-acetyl-β-d-glucosamine at the reducing end

To contribute to the possibilities to study the ability of oligosaccharide fragments of hyaluronic acid to induce angiogenesis, several hyaluronic-acid-related oligosaccharides and their 6-O-sulfated analogues were synthesised as their 4-methoxyphenyl glycosides having 2-acetamido-2-deoxy-d-glucopyranose at the reducing end. In all syntheses described, the d-glucopyranosyluronic acid residue was obtained by oxidation at C-6 of a corresponding d-glucopyranosyl residue after construction of the oligosaccharide backbone, using pyridinium dichromate and acetic anhydride.