反应详情

温度

0 °C

To a stirred solution of dimethyl methylphosphonate (11.73 g, 0.095 mol) in 150 ml of anhydrous THF at -78° C. was added dropwise a solution of n-butyl lithium in hexane (1.67N, 56.7 ml, 0.095 mol) under argon atmosphere, and the mixture was stirred for 30 minutes. To this reaction mixture was added dropwise a solution of methyl cyclohexanecarboxylate (5.6 g, 0.0394 mol) in 10 ml of anhydrous THF. After being stirred for 30 minutes, the reaction mixture was allowed to warm to 0° C., diluted with 5.5 ml of acetic acid and 10 ml of water, and concentrated. 30 ml of water was added to the residue, and the mixture was extracted with ethyl acetate (50 ml×2). The combined ethyl acetate layers were washed with water (20 ml×1) and brine (20 ml×1), dried over anhydrous sodium sulfate, and concentrated. The residue was distilled under reduced pressure to give a colorless transparent oil of dimethyl 2-cyclohexyl-2-oxo-ethylphosphonate (8.62 g, 0.037 mol, yield 93.4%, b.p. 114°-115° C./0.25 mmHg), which was assigned the structure by the following data:

1. stirringAfter being stirred for 30 minutes
2. concentrationconcentrated
3. addition30 ml of water was added to the residue
4. extractionthe mixture was extracted with ethyl acetate (50 ml×2)
5. washThe combined ethyl acetate layers were washed with water (20 ml×1) and brine (20 ml×1)
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated
8. distillationThe residue was distilled under reduced pressure