To a tetrahydrofuran (10 mL) solution of (5-benzyloxy-benzofuran-2-yl)-methanol (561 mg, 2.21 mmol) described in Production Example 7-1-4 were added phthalimide (358 mg, 2.43 mmol), triphenylphosphine (696 mg, 2.65 mmol) and diethylazodicarboxylate (1.21 mL, 2.65 mmol) at 0° C., which was stirred at room temperature for 9 hours. Water was added to the reaction solution at room temperature followed by extraction with ethyl acetate. The organic layer was washed with sat. NaCl followed by drying over anhydrous magnesium sulfate and filtering. The filtrate was concentrated under a reduced pressure and the residue was purified by NH silica gel column chromatography (heptane:ethyl acetate=7:3) to obtain the title compound (635 mg, 75%) as a white solid.
