As a step to synthesize α- and β-sorigenin, the aglycons of the glycosides in the bark of Rhamnus japonica (Fig. 1), two analogous compounds, i. e. lactone of 3-hydroxymethyl-2-naphthoic acid and lactone of 4-hydroxy-3-hydroxymethyl-2-naphthoic acid, were synthesized from 2, 3-naph-thalene-dicarboxylic acid anhydride and 4-hydroxy-2-naphthoic acid, respectively.
