反应详情

Keto-ester 6 (1.0 g, 3.4 mmol) was dissolved in ethanol (50 mL) and palladium catalyst on charcoal (10%, 50 mg) was added. Hydrogenation was performed with 45 psi of hydrogen gas for 20 h. The catalyst was then filtered off and potassium hydroxide (909 mg, 16.2 mmol) was added, and the reaction mixture was refluxed for 1 h. The solvents were evaporated, and aqueous HCl (50 mL, 4.0 M) was added. The acidic aqueous phase was extracted with methylene chloride (3×30 mL), the combined organic extracts were dried over anhydrous magnesium sulfate and evaporated, giving 8 as white crystals (824 mg, 91%). 1H NMR (300 MHz, CDCl3): δ 6.89 (s, 2H), 3.18 (septet, J=6.9 Hz, 2H), 2.64 (t, J=7.7 Hz, 2H), 2.43 (t, J=7.4 Hz, 2H), 1.98 (q, J=7.7 Hz, 2H), 1.29 (d, J=6.9 Hz, 12H). 13C NMR (90.55 MHz, CDCl3): δ 180.51, 149.56, 134.07, 133.52, 123.83, 35.28, 33.98, 27.60, 27.09, 23.21. HRMS (m/z): [M+H]+ calcd. for C16H24O3 263.1653. found 263.1664.

1. filtrationThe catalyst was then filtered off
2. temperaturethe reaction mixture was refluxed for 1 h
3. customThe solvents were evaporated
4. additionaqueous HCl (50 mL, 4.0 M) was added
5. extractionThe acidic aqueous phase was extracted with methylene chloride (3×30 mL)
6. dry with materialthe combined organic extracts were dried over anhydrous magnesium sulfate
7. customevaporated