To a mixture of diisopropylamine (1.1 mL, 7.7 mmol) and tetrahydrofuran (20 mL) was added dropwise n-butyl lithium (1.6 M n-hexane solution, 4.5 mL, 7.1 mmol) at −78° C., which was stirred for 30 minutes at that temperature. Tributyltin hydride (1.7 mL, 6.5 mmol) was added dropwise to the reaction mixture at the same temperature and then stirred for 30 minutes at 0° C. The reaction mixture was cooled to −78° C., and a mixture of 4-benzyloxybenzyl chloride (1.5 g, 6.5 mmol) and tetrahydrofuran (10 mL) was added dropwise at that temperature. The reaction mixture was gradually warmed to room temperature. The reaction mixture was partitioned into water and n-heptane. The organic layer was washed with saturated aqueous sodium chloride, and the solvent was evaporated under a reduced pressure. The residue was purified by neutral silica gel column chromatography (ethyl acetate:heptane=1:30) to obtain the title compound (2.6 g, 83%).
