Selective monoesterification of dicarboxylic acids catalysed by ion-exchange resins

Symmetrical dicarboxylic acids with 4-14 carbon atoms gave selectively the corresponding monoesters in high yields in the transesterification catalyse d by strongly acidic ion-exchange resins in ester-hydrocarbon mixtures. It was found that the rate of the esterification of the dicarboxylic acids is much higher than that of the monocarboxylic acids formed. This result can e xplain the high selectivity for the monoester formation and can also be exp lained by the existence of an aqueous layer on the surface of the resins. T his method of selective esterification is quite simple and practical.