Epoxidation reactions of unsaturated fatty esters with potassium peroxomonosulfate

Epoxidation of the double bond in methyl oleate, octadec-11 E-en-9-ynoate, ricinoleate (12-hydroxy-octadec-9Z-enoate), iso-ricinoleate (9-hydroxy-octadec-12Z-enoate), and 12-oxo-octadec-9Z-enoate with potassium peroxomonosulfate (oxone, 2 KHSO5.KHSO5.K2SO4) in the presence of trifluoroacetone or methyl pyruvate gave the corresponding monoepoxy derivatives. Reaction of Oxone(R) with methyl linoleate and octadeca-9Z,11 E-dienoate furnished the corresponding diepoxystearate derivative. Methyl 9,12-dioxo-octadec-10Z-enoate was obtained when a C-18 furanoid fatty ester (methyl 9,12-epoxy-9,11-octadecadienoate) was treated with Oxone(R). The yield of these reactions was very high (85-99%), and the epoxy derivatives were readily isolated by solvent extraction. The products were identified by spectroscopic methods.