Epoxy acid in seed oils of Malvaceae and preparation of (+) threo ‐12,13‐Dihydroxyoleic acid

Seed oils of six species of Malvaceae , representing four genera, were found to contain cis ‐12,13‐epoxyoleic acid in amounts estimated at 1,5–7% of the total fatty acids. Acetolysis of the oils gave the corresponding dihydroxyoleic acid, which was shown to be predominantly a dextro ‐rotatory form of threo ‐12,13‐dihydroxyoleic acid. It was obtained optically pure, and its structure was confirmed by orthodox methods. The hydrogenation product, (+)‐ threo ‐12,13‐dihydroxystearic acid, was also obtained optically pure and characterized. The best yield of dihydroxyoleic acid was obtained from the seed oil of Malope trifida . Samples of oil from four other species of Malvaeae had a very low or negligible content of epoxy acid.