Location of hydroperoxide groups in monohydroperoxides formed by chlorophyll-photosensitised oxidation of unsaturated esters

Abstract

Monohydroperoxides were isolated from chlorophyll-photosensitised oxidation of methyl oleate, methyl linoleate, methyl linolenate, and ethyl arachidonate. The positions of the hydroperoxide substituent were determined by two methods of analysis of the saturated hydroxy-esters formed by catalytic hydrogenation. Gas–liquid chromatographic analysis of degradation products and mass spectrometric analysis of the corresponding keto-esters both proved that the hydroperoxide groups are located at each of the carbon atoms which originally formed part of a double bond.