反应详情

Sodium bicarbonate (2.29 g, 27.3 mmol, 1.05 equiv) was added to a solution of hydroxylamine hydrochloride (1.94 g, 27.3 mmol, 1.05 equiv) in water (100 mL) at room temperature. After the evolution of gas ceased (approx. 30 min), a solution of ethyl 2-methyl-2-(methylsulfonyl)-5-oxopentanoate (6.14 g, 26.0 mmol, 1.0 equiv) in ethanol (100 mL) was added dropwise over 30 min, and the reaction was allowed to stir overnight (approx. 15 h). The reaction mixture was concentrated under reduced pressure to half the volume (approx. 100 mL) and partitioned between dichloromethane (200 mL) and water (100 mL). The aqueous phase was extracted with dichloromethane (100 mL). The combined organic phases were dried over anhydrous magnesium sulfate and concentrated under reduced pressure to provide the title compound (6.4 g, 97%, approx. 1:1 mixture of E/Z isomers). MS (LCMS) m/z 252.1 (M+1). 1H NMR (400 MHz, CHLOROFORM-d) δ1.34 (td, J=7.12, 1.17 Hz, 6H) 1.56-1.72 (m, 6H) 2.11-2.19 (m, 2H) 2.19-2.29 (m, 1H) 2.44 (d, J=3.71 Hz, 4H) 2.51-2.63 (m, 1H) 3.06 (d, J=2.93 Hz, 6H) 4.30 (qd, J=7.12, 3.22 Hz, 4H) 6.66-6.88 (m, 1H) 7.43 (d, J=5.07 Hz, 1H).

1. custom(approx. 30 min)
2. concentrationThe reaction mixture was concentrated under reduced pressure to half the volume (approx. 100 mL)
3. custompartitioned between dichloromethane (200 mL) and water (100 mL)
4. extractionThe aqueous phase was extracted with dichloromethane (100 mL)
5. dry with materialThe combined organic phases were dried over anhydrous magnesium sulfate
6. concentrationconcentrated under reduced pressure