A convenient synthesis, following suggested path of biogenesis, of catenarin and erythroglaucin has been made. It involves nuclear oxidation of the corresponding benzoyl benzoic acid. This reaction and the following ring closure give very good yields of catenarin dimethyl ether. Complete demethylation yields catenarin and partial demethylation erythroglaucin which can also be formed by the partial methylation of catenarin.