P(=O)([O-])O[C:3](CC)(CC)[S:4][C:5]1[CH:10]=[CH:9][C:8]([O:11][CH3:12])=[CH:7][CH:6]=1.[Li]CCCC.[Si:24]([O:31][C@H:32]([CH3:35])[CH:33]=O)([C:27]([CH3:30])([CH3:29])[CH3:28])([CH3:26])[CH3:25]>O1CCCC1>[Si:24]([O:31][C@H:32]([CH3:35])/[CH:33]=[CH:3]/[S:4][C:5]1[CH:10]=[CH:9][C:8]([O:11][CH3:12])=[CH:7][CH:6]=1)([C:27]([CH3:28])([CH3:29])[CH3:30])([CH3:25])[CH3:26]Under the nitrogen atmosphere, 3.24g (11 mmole) of diethyl-p-methoxyphenylthiomethyl phosphonate was dissolved in 50 ml of anhydrous tetrahydrofuran and after lowering the reaction temperature to -78° C., 6.87 ml (11 mmole) of 1.6M n-BuLi was added to the mixture for ten minutes. The resultant mixture was agitated at the temperature of -78° C. for 30 minutes. At the same temperature, 1.87 g (10 mmole) of (2R)-2-(t-butyldimethylsilyloxy)propanal diluted with 10 ml of anhydrous tetrahydrofuran was added to the said reaction mixture and the reaction temperature raised to 0° C., and then the mixture agitated at 0° C. for another 1.5 hours. Once the reaction was completed, the reaction was quenched by adding saturated ammonium chloride solution. After the work-up treatment in the same manner as did in method A of EXAMPLE 32, the crude product (2.92 g) obtained therefrom was purified by a column chromatography (using n-hexane containing 3% diethyl ether as an eluent), thereby 2.59 g of desired compound having E/Z ratio of over 100/1 (yield: 80%) was stereoselectively obtained.
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