Thermal conversions of trimethylsilyl peroxides of linoleic and linolenic acids

The trimethylsilyl (TMS) peroxides/esters of the fatty acid hydroperoxides (9S,10E,12Z)-9-hydroperoxy-10,12-octadecadienoic acid (9-HPOD) and (9Z,11E,13S,15Z)-13-hydroperoxy-9,11,15-octadecatrienoic acid (13-HPOT) were subjected to gas chromatography-mass spectrometry and products formed by thermal rearrangements were identified. The main products were decadienals and the TMS derivatives of 13-oxo-9,11-tridecadienoic acid, epoxyalcohols, hemiacetals, and ketodienes. Oxy radicals as well as epoxyallylic radicals served as intermediates in the formation of these compounds. The thermal TMS peroxide conversions documented provided biomimetic models for enzymatic conversions of fatty acid hydroperoxides and also offered a method to generate an array of oxylipin derivatives of value as reference compounds in GC-MS studies.