56] - Oxidation of Carbohydrates with Dimethyl Sulfoxide-Acetic Anhydride: Methyl α-D-erythro-Pentopyranosid-3-ulose

Abstract

Publisher Summary This chapter discusses the oxidation of carbohydrates with dimethyl sulfoxide–acetic anhydride. Primary and secondary alcohols are oxidized by dimethyl sulfoxide (DMSO) to aldehydes and ketones respectively. The reaction requires the presence of an activating, electrophilic reagent. Because of very mild reaction conditions, these reactions have become important in carbohydrate chemistry. Yields are often highest with dicyclohexylcarbodiimide (DCC). However, this procedure sometimes fails with carbohydrates having a sterically hindered hydroxyl group. Such substances may be oxidized by using acetic anhydride or phosphorus pentaoxide instead of DCC, but these latter two reagents also lead to the formation of methylthiomethyl ethers as byproducts and with acetic anhydride some acetylation may occur. An advantage of the DMSO-acetic anhydride procedure is that the reaction product may be isolated by lyophilization of the reaction mixture.