Catalytic carboxylation of fats. Carboxy acids and esters from monounsaturates

Abstract

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.