Acetylation of Sugars

Abstract

THE acetylation of sugars has hitherto involved the use of acetic anhydride and a catalyst such as sodium acetate¹, zinc chloride², sulphuric acid³ or pyridine⁴. We have shown that glucose may be acetylated rapidly by means of a mixture of acetic anhydride and acetic acid if a small amount of perchloric acid is added to act as a catalyst⁵. No external application of heat is necessary to aid the reaction. By pouring the acetylation mixture into water, an almost quantitative yield of α-pentacetyl glucose is produced. This new procedure does not afford crystalline acetyl derivatives of galactose or mannose ; but it works well for the acetylation of maltose, difructofuranose anhydride,α-methyl-glucoside, and polyhydric alcohols such as mannitol, sorbitol, erythritol, arabitol and pentaerythritol.