反应详情

温度

23 °C

Sodium hydroxide (1.4 g, 35 mmol) is added to a solution of (E)-ethyl 2-methyl-7-phenyl-hept-2-enoate (8.6 g, 35 mmol) in MeOH (40 mL) and water (2 mL) at 0° C. The reaction is stirred at 23° C. for 2 hours and then heated at 50° C. for 24 hours. After cooling, the reaction is concentrated in vacuo and partitioned between 2N HCl (15 mL) and CH2Cl2 (60 mL). The aqueous layer is back-extracted with CH2Cl2 (2×30 mL) and the organic layers are combined and dried (MgSO4). The solution is concentrated in vacuo and purified by gradient elution chromatography (silica, 20 to 40% ether in petroleum ether) to yield (E)-2-Methyl-7-phenyl-hept-2-enoic acid (4.9 g, 65%): 1H NMR (CDCl3) δ 7.30-7.23 (m, 2H), 7.20-7.14 (m, 3H), 6.90 (dt, J=15.4, 1.3 Hz, 1 H), 2.62 (t, J=7.5 Hz, 2H), 2.22 (q, J=7.0 Hz, 2H), 1.81 (s, 3H), 1.69-1.58 (m, 2H), 1.55-1.43 (m, 2H); MS (FAB) m/e 219 (M+H)+.

1. temperatureheated at 50° C. for 24 hours
2. temperatureAfter cooling
3. concentrationthe reaction is concentrated in vacuo
4. custompartitioned between 2N HCl (15 mL) and CH2Cl2 (60 mL)
5. extractionThe aqueous layer is back-extracted with CH2Cl2 (2×30 mL)
6. dry with materialdried (MgSO4)
7. concentrationThe solution is concentrated in vacuo
8. custompurified by gradient elution chromatography (silica, 20 to 40% ether in petroleum ether)