Catalytic carboxylation of fats. Carboxy acids and esters from monounsaturates

TLDR: In this article, a highly selective catalytic, one-step synthesis of oleic acid into 9(10)-carboxystearic acid in high yields is described.

Abstract: A highly selective catalytic, one-step synthesis converts oleic acid into 9(10)-carboxystearic acid in high yields (85–99%). Hydrocarboxylation with water and carbon monoxide under pressure (3000–4000 psi) is catalyzed with a mixture of palladium chloride and triphenylphosphine at 120–150 C with or without acetone or acetic acid solvents. Palladium supported on carbon is also an effective hydrocarboxylation catalyst in the presence of triphenylphosphine and HCl. Methyl 9(10)-carbomethoxystearate was prepared by catalytic carbomethoxylation of methyl oleate with methanol and carbon monoxide but in lower yields. The carboxystearic acids and esters consisted of the 9 and 10 isomers (87–94%) in approximately equal proportions. This catalytic carboxylation procedure is a more efficient route to carboxystearic acid and ester than the two-step hydroformylation-oxidation process reported previously. Carboxylated acids, methyl esters and triglycerides of potential industrial importance have been prepared.