A method for locating the O-acetyl groups in secondary cellulose acetates

Abstract

A procedure for replacing the labile O-acetyl groups in secondary cellulose acetate with the stable O-methyl group is described. After hydrolysis, the methylated sugars so formed are analysed by gas chromatography. In the absence of group migration during the replacement reactions, the position of the O-methyl groups indicates the position of the O-acetyl groups in the cellulose acetate. Examples of O-acetyl distribution found in cellulose acetates made by different methods are given. Hydrolysis of the cellulose acetates with sulphuric acid–barium carbonate followed by reduction with sodium borohydride revealed mannitol, presumably an artifact.