Abstract
Synthesis of 1-hydroxy-3-hydroxymethyl-4-(3, 4-dimethoxyphenyl)-6, 7-methylenedioxy-2-naphthoic acid γ-lactone (I), the structure assigned to diphyllin by T. Murakami in 1961, was carried out by starting from 3, 4-dimethoxy-3', 4'-methylenedioxybenzophenone (III) as shown in Chart 1. Cyclization of benzhydrylsuccinic acid (V) derived from III occurred selectively on the benzene ring bearing no bromo group as expected. Nonidentity of I with diphyllin was confirmed by comparison of melting points, infrared spectra, thin-layer chromatograms and ferric chloride tests.
