反应详情

To a solution of dimethyl methylphosphonate (2.4 ml, 21.8 mmol) in 100 ml of anhydrous THF was added dropwise n-butyl lithium (1.49N, 14.7 ml, 21.8 mmol) at -78° C. under argon atmosphere. After the mixture was stirred for 30 minutes, methyl 2,2-dimethyl-3-phenylpropionate (1.75 g, 10.0 mmol) was added dropwise and the mixture was stirred at -78° C. for 20 minutes and then at room temperature overnight. To this reaction mixture was added an aqueous saturated solution of ammonium chloride, and the mixture was extracted with ethyl acetate (50 ml×4). Then, the combined ethyl acetate layers were washed with water (50 ml) and brine (50 ml), dried over anhydrous sodium sulfate, and concentrated. Purification by column chromatography (silica gel, ethyl acetate) yielded a pure product of dimethyl 3,3-dimethyl-2-oxo-4-phenylbutylphosphonate (2.3144 g, 8.14 mmol, 89.5%). This compound was assigned the structure by the following data: m.p. 39° -46° C. (colorless needle-like crystal)

1. stirringthe mixture was stirred at -78° C. for 20 minutes
2. customat room temperature
3. customovernight
4. extractionthe mixture was extracted with ethyl acetate (50 ml×4)
5. washThen, the combined ethyl acetate layers were washed with water (50 ml) and brine (50 ml)
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated
8. customPurification by column chromatography (silica gel, ethyl acetate)