反应详情

温度

80 °C

A solution of compound 3 (163.09 g, 375 mmol) in EtOH (750 mL) was charged with concentrated aqueous HCl (150 mL) and the resulting solution heated at 80° C. for 90 min. The solution was allowed to cool to RT and then was concentrated to the aqueous layer. H2O (500 mL) was added and the mixture extracted with CH2Cl2 (3×150 mL). The combined organic layers were dried (MgSO4) and concentrated to provide 4 (119.78 g, 93% over 2 steps) as a brown oil (3:1 mixture of Z:E isomers). The mixture was carried on without further purification. Z-isomer: 1H NMR (400 MHz, CDCl3): δ 0.94 (t, J=7.5 Hz, 3H), 2.45 (q, J=7.5 Hz, 2H), 3.68 (s, 3H), 6.56 (d, J=8.6 Hz, 2H), 6.75 (d, J=8.6 Hz, 2H), 7.08-7.21 (m, 5H), 7.41 (d, J=8.1 Hz, 2H), 7.87 (d, J=8.1 Hz, 2H), 10.02 (s, 1H). E-isomer: 1H NMR (CDCl3): δ 0.97 (t, J=7.4 Hz, 3H), 2.52 (q, 7.4 Hz, 2H), 3.83 (s, 3H), 6.90 (d, J=8.3 Hz, 2H), 7.03 (d, J=8.3 Hz, 2H), 7.0-8-7.21 (m, 7H), 7.51 (d, J=8.1 Hz, 2H), 9.83 (s, 1H).

1. temperatureto cool to RT
2. concentrationwas concentrated to the aqueous layer
3. additionH2O (500 mL) was added
4. extractionthe mixture extracted with CH2Cl2 (3×150 mL)
5. dry with materialThe combined organic layers were dried (MgSO4)
6. concentrationconcentrated
7. customto provide 4 (119.78 g, 93% over 2 steps)
8. additionas a brown oil (3:1 mixture of Z:E isomers)
9. customThe mixture was carried on without further purification