Hydroperoxides formed by ferrous ion-catalyzed oxidation of methyl linolenate

An emulsion of methyl linolenate was allowed to oxidize with a catalyst of ferrous sulfate and ascorbic acid. Three oxidation products were isolated, and their hydrogenated derivatives were characterized as the isomeric mixture of methyl monohydroxyoctadecanoate (monoOH), methyl 9,16-dihydroxyoctadecanoate (diOH), and the isomeric mixture of methyl trihydroxyoctadecanoate (triOH). The monoOH isomers and diOH apparently were derived from methyl monohydroperoxyoctadecatrienoate (monoHPO) and methyl dihydroperoxyoctadecatrienoate (diHPO), respectively. Two triOH isomers (the 9,10,12- and 13,15,16-isomers) were thought to be derived from the products containing cyclic peroxide-hydroperoxide structure. 9,16-diHPO was produced by the incubation of monoHPO with ferrous sulfate and ascorbic acid. Moreover, the experiment using¹⁸O₂ demonstrated that mono-HPO yielded 9,16-diHPO by reacting with oxygen molecule. 9,10,13- and/or 9,12,13- and 12,13,16- and/or 12,15,16-triOH isomers were also detected in the hydrogenated derivatives of oxidation products from monoHPO.