Peroxidation of polyunsaturated fatty acid methyl esters catalyzed by N-methyl benzohydroxamic acid: a new and convenient method for selective synthesis of hydroperoxides and alcohols.

A new catalytic system, based on N-methyl benzohydroxamic acid (NMBHA), was developed for the selective synthesis of lipid hydroperoxides and alcohols by aerobic oxidation of lipid precursors. The reactions were carried out under mild conditions with air at atmospheric pressure and 37 degrees C. The products were isolated in much better yields (50-60%) as compared to previously reported procedures. NMBHA can be recovered at the end of the reaction and recycled. The putative reactive intermediate, a nitroxyl radical, readily abstracts a hydrogen atom from polyunsaturated lipid precursors such as linoleate esters, and NMBHA itself is an excellent hydrogen atom donor, thus conferring high selectivity to oxidations catalyzed by this reagent.