反应详情

温度

-78 °C

n-Butyl lithium (1.49N, 28.3 ml, 42.2 mmol) was added dropwise to a solution of diisopropylamine (5.9 ml, 42.2 mmol) in 50 ml of anhydrous THF at -78° C. under argon atmosphere. After the mixture was stirred at -78° C. for 20 minutes, methyl 2-methyl-3-phenylpropionate (5.00 g, 28.1 mmol) was added dropwise. After the mixture was stirred at -78° C. for 30 minutes, a solution of methyl iodide (2.6 ml, 42.2 mmol) in HMPA (1.5 ml, 8.43 mmol) was added dropwise. The reaction mixture was further stirred at -78° C. for 2 hours, and 10 ml of an aqueous saturated solution of ammonium chloride was added. The mixture was extracted with ether (50 ml×4), and then, the combined ether layers were washed with water (50 ml) and brine (50 ml), dried over anhydrous sodium sulfate, and concentrated. This residue was distilled to give a colorless oil of methyl 2,2-dimethyl-3-phenylpropionate (1.8909 g, yield 51.7%, b.p. 127.5°-131° C./18 mmHg), which was assigned the structure by the following data:

1. stirringAfter the mixture was stirred at -78° C. for 30 minutes
2. stirringThe reaction mixture was further stirred at -78° C. for 2 hours
3. extractionThe mixture was extracted with ether (50 ml×4)
4. washthe combined ether layers were washed with water (50 ml) and brine (50 ml)
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationconcentrated
7. distillationThis residue was distilled