Decomposition of linoleate hydroperoxides: precursors of oxidative dimers.

When hydroperoxides are thermally decomposed in the presence of unsaturated fatty acids, dimers are formed in amounts equivalent to the hydroperoxide present. The origin of these dimers has not been shown by any definitive experiment. Radioactively (14C) labeled materials now have been used to determine whether (1) two molecules of hydroperoxide react, (2) a hydroperoxide and an unoxidized fatty acid molecule form the dimer, or (3) two molecules of unoxidized fatty acid dimerize with hydroperoxide catalysis. Methyl Iinoleate hydroperoxide and unoxidized methyl Iinoleate were reacted in experiments, first with the HC-labeled hydroperoxide and then with 14C-labeled ester. The radiotracer experiments-indicate that the dimer is formed from a molecule of the hydroperoxide and a molecule of the fatty ester.