The above-obtained 2-(benzyloxymethyl)-4,6-bis(methoxymethoxy)benzoic acid (20 mg, 0.054 mmol) was dissolved in methanol (2 mL) and the obtained solution was added with 2.0 mol/L trimethylsilyldiazomethane-hexane solution (0.30 mL, 0.60 mmol), followed by stirring at a room temperature for 1 hour. The reaction mixture was added with acetic acid (0.050 mL) and the solvent was evaporated under reduced pressure. The residue was purified by preparative thin-layer chromatography (chloroform/methanol=100/1) to obtain 2-(benzyloxymethyl)-4,6-bis(methoxymethoxy)benzoic acid methyl ester (12 mg, 57%).
