Synthesis of (E)-13-n-hexyloxacyclicotridec-10-en-2-ona (macrolactone) by transesterification of castor oil using heterogeneous catalysts based on zinc oxide

Abstract

This work reports the results obtained from the transesterification of castor oil with methanol under soft conditions(low temperature and atmospheric pressure), employing basic solids as Ba/ZnO, Mg/ZnO, and K/ZnO. It was foundthat the different systems exhibit high catalytic activity for the transformation of castor oil, but the Ba/ZnO systemshowed a highest tendency toward cyclation of ricinoleic acid to form a product known as macrolactone, namelly (E)-13-n-hexyloxacyclictridec-10-en-2-ona. The catalytic systems were analyzed through FT-IR, TEM, SEM, X-raydiffraction, temperature programmed reduction, analysis of surface area and the esters obtained from the reactionwere analyzed by gas chromatography coupled to mass spectroscopy (GC-MS).