反应详情

To a solution of 8 (3.24 g, 18.0 mmol) in dry CH2Cl2 (50 mL) at 0° C. was added N-bromosuccinimide (3.56 g, 20.0 mmol) portion-wise and the reaction was warmed to room temperature and stirred for 12 h. Solvent was then removed in vacuo and the product was purified by flash column chromatography (EtOAc/hexane, 5:95, v:v, Rf=0.1) and resulted in a colorless oil as a 2:1 mixture of trans:cis diastereomers; 1H NMR (CDCl3, 500 MHz): δ 6.86-6.81 (m, 2 H), 6.72 (dd, J=4.6, 8.6 Hz, 1 H), 4.22 (m, 1 H), 4.03 (m, 1 H), 3.78 (s, 3H), 3.44 (dd, J=4.3, 9.7 Hz, 1 H), 3.34 (dd, J=6.4, 9.7 Hz, 1 H), 2.6 (t, J=7.3 Hz, 2 H), 2.13 (m, 1 H), 2.05 (m, 1 H), 1.75 (m, 1 H), 1.67-1.46 (m, 5 H).

1. customSolvent was then removed in vacuo
2. customthe product was purified by flash column chromatography (EtOAc/hexane, 5:95, v:v, Rf=0.1)
3. customresulted in a colorless oil as a 2:1 mixture of trans