Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → Ethyl 3-(3-(benzyloxy)-4-methylphenyl)acrylate

Under a nitrogen atmosphere, to a solution of 3-(benzyloxy)-4-methylbenzaldehyde (2.50 g) in toluene (50 mL) was added ethyl (triphenylphosphoranylidene)acetate (4.20 g), and the mixture was stirred at 70° C. for 15 hr. The reaction mixture was concentrated, diethyl ether (100 mL) was added, and the insoluble material was filtered off. The filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/hexane) to give the title compound (2.50 g) as a colorless oil. This compound was used for the next step without further purification.