Selectively Protected Disaccharide Building Blocks for Modular Synthesis of Heparin Fragments

Abstract

A modular approach for the synthesis of heparin fragments is described. Levulinoyl esters were employed to protect those hydroxy groups intended to be sulfated in the final product, while acetyl esters and benzyl ethers were used as the permanent protecting groups. A highly efficient chemoenzymatic reaction sequence was used for the deprotection of an O-sulfated fragment, while the final stage of the synthesis entailed a selective oxidation of a primary alcohol of a glucoside with TEMPO/NaOCl to give a glucuronic acid moiety. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)