反应详情

A mixture of ethyl isobutyrylacetate (20.47 g, 129 mmol) and 1.5 M aq NaOH (250 mL) is stirred at room temperature overnight. The solution is then cooled to 0° C. and acidified to pH 1-2 by the slow addition of conc. HCl (˜35 mL). The solution is then saturated with NaCl and extracted thrice with EtOAc and once with CHCl3. The combined extracts are dried over Na2SO4 and concentrated to 14.46 g (86%) of isobutyrylacetic acid as an oil. 1H NMR (CDCl3, 300 MHz) reveals a mixture of keto and enol forms (˜4:1), in favor of the keto form. Keto form: δ 3.57 (s, 2H), 2.73 (sept, J=6.9 Hz, 1H), 1.16 (d, J=6.9 Hz, 6H) ppm. Enol form: 11.85 (s, 1H), 5.03 (s, 1H), 2.44 (sept, J=6.9 Hz, 1H) 1.10 (d, J=6.9 Hz, 6H) ppm.

1. temperatureThe solution is then cooled to 0° C.
2. extractionsaturated with NaCl and extracted thrice with EtOAc
3. dry with materialThe combined extracts are dried over Na2SO4
4. concentrationconcentrated to 14.46 g (86%) of isobutyrylacetic acid as an oil
5. additiona mixture of keto and enol forms (˜4:1)