CATALYTIC EPOXIDATION OF METHYL LINOLEATE - CYCLIZATION PRODUCTS OF THE EPOXYACID ESTERS

The few studied catalytic epoxidation of 1,4-dienes by hydroperoxide a nd metallic catalyst has been investigated with methyl linoleate. Besi des the expected diepoxy derivatives dihydroxy tetrahydrofurans were o btained. Their yield can reach 75 % mainly with the supported MoO3-(t) .butylhydroperoxide system. They were identified as methyl 10,13-epoxy -9, 12-dihydroxy-octadecanoate and methyl 9,12-epoxy-10, 13-dihydroxy- octadecanoate . Every regioisomer exhibits two configurations, syn and anti, readily separated by chromatography and identified by proton NM R. Synthesis of the so-called dihydroxy-THF seems to be caused by the formation of molybdic acid from MoO3 and TBHP. Molybdic acid is able t o open the oxirane ring and to induce the intramolecular cyclisation, but only when TBHP is present. The reaction mechanism needs some addit ional. investigations, which are in progress.