反应详情

Concentrated H2SO4 (2.35 mL, 44.0 mmol) was added dropwise to ethyl 2-cyano-3,3-dimethyl-4-phenylbutanoate (1.08 g, 4.4 mmol) at 0° C. to give an orange solution. The reaction was allowed to warm to room temperature and was stirred for 24 h. Ice water (10 mL) was added to the deep red reaction to give an opaque yellow mixture. The reaction was basified with NH4OH (20 mL) and extracted with ether (3×10 mL). The organic extracts were washed with water and brine, dried over Na2SO4, and concentrated under reduced pressure to give bright yellow oil. Purified by flash column chromatography (20% ethyl acetate in hexanes, Rf=0.30) afforded the title compound as bright yellow crystalline solid (392.4 mg, 36.4% yield). 1H NMR (500 MHz, CDCl3) δ 7.39 (d, J=7.5 Hz, 1H), 7.31-7.28 (m, 2H), 7.18 (d, J=7.2 Hz, 1H), 6.33 (s, 2H), 4.26 (q, J=7.1 Hz, 2H), 2.65 (s, 2H), 1.34 (t, J=7.1 Hz, 3H), 1.20 (s, 6H).

1. customto give an orange solution
2. customto give an opaque yellow mixture
3. extractionextracted with ether (3×10 mL)
4. washThe organic extracts were washed with water and brine
5. dry with materialdried over Na2SO4
6. concentrationconcentrated under reduced pressure
7. customto give bright yellow oil
8. customPurified by flash column chromatography (20% ethyl acetate in hexanes, Rf=0.30)