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

Seed oils of six species ofMalvaceae, representing four genera, were found to containcis‐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 adextro‐rotatory form ofthreo‐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 ofMalope trifida. Samples of oil from four other species ofMalvaeae had a very low or negligible content of epoxy acid.