4-Oxo-5, 7-dimethoxy-1, 2, 3, 4-tetrahydro-2-naphthoic acid (VII) is expected to serve as a key intermediate in the synthesis of the proposed structure for α-sorigenin dimethyl ether (3-hydroxymethyl-1, 6, 8-trimethoxy-2-naphthoic acid γ-lactone (I)). The reported method for VII was improved and the synthesis of 3-hydroxymethyl-4, 5, 7-trimethoxy-2-naphthoic acid γ-lactone (II) started with VII was carried out. The reaction scheme is shown in chart.