215 g (0.60 mole) of methyltriphenylphosphonium bromide and 54 g (0.48 mole) of potassium t-butoxide were added to 2 liters of dried benzene, and the mixture was stirred for 9 hours at room temperature. At the end of this time, 40 g (0.12 mole) of 3-(3,4-dichlorophenyl)-3-oxo-1-propanol t-butyldimethylsilyl ether [prepared as described in step (b) above] were dissolved in 800 ml of benzene and the resulting solution was slowly added dropwise to the mixture over a period of 2.5 hours. 1 liter of water was then added to the reaction mixture, and the mixture was stirred for 30 minutes, whilst ice-cooling. The organic layer was separated, and then washed with water and with a saturated aqueous solution of sodium chloride, after which it was dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure, and the resulting residue was purified by silica gel column chromatography, using hexane as the eluent, to give 23.5 g of the title compound. The physicochemical properties of this product were the same as those of the product produced as described in Example 1(b).
