Synthesis of (E)-and (Z)-α,β-DifluorourocanicAcid. -The synthesis of title compounds (VII) and (VIII) starts from the isomeric α-fluoropropenoates (I). The installation of the fluorine in the β-position is accomplished by regiospecific "FBr" addition to the mixture of alcohols (II) followed by HBr elimination. Neither acid (VII) nor isomer (VIII) are an inhibitor of urocanase. -(HAJDUCH, J.; DOLENSKY, B.; YOSHIDA, S.; FAN, J.; KIRK*, K. L.; J.