The selective hydrogenation of linolenic acid

The hydrogenated samples were analyzed by ultraviolet specconditions produced mostly nonselective hydrogenation. The variables of catalyst, catalyst concentration, solvent, temperature, and pressure have very little effect on the selectivity. Large differences were found in the relative reactivities of the three double bonds in methyl linoleate. It appears that the initial reaction strongly favors the 12 position assuming a limited amount of shifting of double bonds during hydrogenation. The solvent has an appreciable effect on this selectivity, but the other variables have only minor effects. The hydrogenated samples were analyzed by ultraviolet spectroscopy. Efforts to identify the location of the double bonds by oxidative methods were unsatisfactory. Preliminary studies on the possible use of nuclear spin resonance as analytical method in fatty acid analysis look promising.