Hydrolysis of mono- and diepoxyoctadecanoates by alumina

In this study it is shown that the epoxide derivative of oleic acid, methyl 9,10-epoxyoctadecanoate, is readily hydrolyzed to a diol when exposed to a commercial preparation of neutral alumina. Comparison of H-1 and C-13 NMR spectra of the diol with those of standards showed that the product was the threo isomer. When methyl 9,10-12,13-diepoxyoctadecanoate was treated with alumina, a mixture of dihydroxytetrahydrofuran regioisomers, methyl 9,12-epoxy-10,13-dihydroxystearate and methyl 10,13-epoxy-9,12-dihydroxystearate, was obtained. These results show that alumina is an unsuitable support for epoxidation catalysts. However, alumina-catalyzed hydrolysis of fatty epoxides is an efficient way to synthesize polyhydroxy materials, and these materials are suitable for several industrial applications.