反应详情

温度

0 °C

To a suspension of sodium hydride (60% dispersion in mineral oil, 475 mg, 11.9 mmol) in diethyl ether (25 mL) at 0° C. was added ethanol (0.06 ml, 1.03 mmol) dropwise. The grey suspension was stirred at 0° C. for 20 min. A solution of 3,3-dimethylcyclohexanone (1.50 g, 11.9 mmol) and ethyl formate (1.45 ml, 17.8 mmol) in diethyl ether (3 mL) was added dropwise over 10 min. The yellow heterogeneous reaction mixture was stirred at 0° C. for 1 h then warmed to room temperature and stirred for 2 h. Ethanol (1 mL) was added and the mixture was stirred at room temperature for 1 h then quenched with water (25 mL). The layers were separated and the aqueous phase was washed with diethyl ether. The aqueous layer was acidified with 1M HCl until pH=2 and then extracted with diethyl ether (2×). The combined organic layers were dried over MgSO4 and concentrated to afford 1.64 g (90%) of 2-[1-hydroxy-meth-(Z)-ylidene]-5,5-dimethyl-cyclohexanone as a light yellow oil. 1H NMR (CDCl3, 400 MHz): δ (ppm) 14.38 (br. s., 1H), 8.79 (s, 1H), 2.34-2.47 (m, 2H), 2.16 (s, 2H), 1.42-1.53 (m, 2H), 1.00 (s, 6H).

1. stirringThe yellow heterogeneous reaction mixture was stirred at 0° C. for 1 h
2. temperaturethen warmed to room temperature
3. stirringstirred for 2 h
4. stirringthe mixture was stirred at room temperature for 1 h
5. customthen quenched with water (25 mL)
6. customThe layers were separated
7. washthe aqueous phase was washed with diethyl ether
8. extractionextracted with diethyl ether (2×)
9. dry with materialThe combined organic layers were dried over MgSO4
10. concentrationconcentrated