反应详情

To a solution of dimethyl methylphosphonate (6.1 ml, 56.0 mmol) in 100 ml anhydrous THF was added dropwise n-butyl lithium (1.61N, 34.7 ml, 55.9 mmol) at -78° C. under argon atmosphere. After stirring the mixture for 15 minutes, ethyl 2,2-dimethylnonanoate (5.00 g, 23.3 mmol) was added dropwise and the mixture was stirred at -78° C. for 20 minutes and then at room temperature for 2 hours. To the reaction mixture was added 20 ml of saturated aqueous solution of ammonium chloride. The mixture was extracted with ethyl acetate (50 ml×4). The ethyl acetate layers were washed with water (50 ml) and with brine (50 ml), dried over anhydrous sodium sulfate, and concentrated. Purification by column chromatography on silica gel (ethyl acetate) gave pure dimethyl 3,3-dimethyl-2-oxodecylphosphonate (2.3312 g, 7.97 mmol, yield 34%). The structure of this product was confirmed by the following data.

1. stirringthe mixture was stirred at -78° C. for 20 minutes
2. waitat room temperature for 2 hours
3. extractionThe mixture was extracted with ethyl acetate (50 ml×4)
4. washThe ethyl acetate layers were washed with water (50 ml) and with brine (50 ml)
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationconcentrated
7. customPurification by column chromatography on silica gel (ethyl acetate)