The structure of 3a was confirmed unambiguously by X-ray crystallographic analysis, 19a which showed that the hydroxyl group, the phenyl group and the styryl group adopt a cis conformation. Exceptionally, para-bromo-substituted 4g underwent the reaction to give 5g in 62% yield. In addition, the steric effect was clearly demonstrated for substrates with substituents at para-, meta-or ortho-position of phenyl rings. As a result, the corresponding products were obtained in reduced yields in turn (5b, 5h, 5i and 5c, 5j, 5k). When substrate 4l was checked, the product 5l was obtained in lower yield compared to mono-methoxy substituted substrates. We concluded that two electron-donating methoxyl groups lowered the reactivity of α-oxo-β, γ-unsaturated ketone 4l