Purity >95%. (±)14(15)-EE-8(Z)-E is a potent vasodilator in bovine coronary arteries. The synthesis of this analog involves the formation of the epoxide at the 14,15-double bond, however, epoxidation can also occur at the 8,9-double bond. (±)8(9)-EE-14(Z)-E is a minor product from the synthesis of (±)14(15)-EE-8(Z)-E. This compound has not been reported in the literature, and its biological activity is not known. It may serve as a tool to verify that the parent compound, (±)14(15)-EE-8(Z)-E, is pure and does not contain the 8,9-epoxy regioisomer.