反应详情

Ethyl acetoacetate (1g, 7.68 mmol) was added dropwise to a suspension of NaH (60% in mineral oil, 338 mg, 8.45 mmol) in toluene (20 mL). The resulting suspension was stirred at rt for 10 min, then treated with l-bromopinacolone (1.3g, 7.32 mmol). The mixture was immersed in a 75° C. oil bath, and stirred under Ar for 1 h. The reaction was cooled to rt, diluted with toluene and washed with H2O (2×50 mL). The organic layer was dried over Na2SO4, filtered and concentrated in vacuo to afford crude ethyl 2-acetyl-5,5-dimethyl-4-oxo-hexanoate (1.46g) which was not purified: 1H NMR (CDCl3, chemical shifts in ppm relative to TMS): 1.166 (s, 9H), 1.277 (t, 3H, J=7.1 Hz), 2.368 (s, 3H), 3.000 (dd, 1H, J=5.8 Hz, J=18.4 Hz), 3.231 (dd, 1H, J=8.2 Hz, J=18.4 Hz), 4.010 (dd, 1H, J=5.8 Hz, J=8.2 Hz), 4.191 (q, 2H, J=7.1 Hz); Field Desorption Mass Spectrometry: m/z 229 (M+1).

1. customwas immersed in a 75° C.
2. stirringstirred under Ar for 1 h
3. temperatureThe reaction was cooled to rt
4. washwashed with H2O (2×50 mL)
5. dry with materialThe organic layer was dried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated in vacuo