Synthesis of β(1–4)-Linked Disaccharides of N-Acetylglucosamine and N-Acetylmuramic Acid by Their Direct Condensation

As a basic study in the synthetic approach to immunoactive cell wall peptidoglycan whose backbone is a β(1–4)-linked saccharide of alternating glucosamine and muramic acid, methods for the direct condensation of these sugar components were studied and O-(N-acetyl-β-muramyl)-(1→4)-N-acetyl-d-glucosamine and O-(N-acetyl-β-d-glucosaminyl)-(1→4)-N-acetylmuramic acid were synthesized. In the synthesis of the latter disaccharide, previous formation of an ester bond between the carboxyl group of muramic acid and the 6-hydroxyl group of glucosamine proved to facilitate the glycoside bond fromation between these sugar moieties.