反应详情

温度

-78 °C

Compound 8a (2.23 g, 6.73 mmol) was dissolved in 80 ml of CH2Cl2 and cooled to −78° C. 1M boron tribromide solution in dichloromethane (20 ml) was added dropwise and the mixture was allowed to warm to ambient temperature and was stirred overnight. Sat. NaHCO3 was added and the product extracted with dichloromethane, dried over Na2SO4, filtered, and concentrated to yield the crude product. Column chromatography (7:2:1; CH2Cl2:MeOH:Et3N) afforded 1.62 g (76%) of 9a as brown wax. 1H NMR (400 MHz, CDCl3) δ ppm 0.84-0.87 (t, 3H, J=6 Hz), 1.27-1.31 (m, 2H), 1.70-1.82 (m, 3H), 2.25-2.28 (m, 1H), 2.58-2.06 (m, 1H), 2.73-2.78 (m, 4H), 2.97-3.09 (m, 5H), 3.16-3.20 (m, 7H), 6.45 (s, 1H), 6.53-6.55 (d, 1H, J=9.2 Hz), 6.84-6.86 (d, 1H, J=8 Hz).

1. temperatureto warm to ambient temperature
2. extractionthe product extracted with dichloromethane
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated
6. customto yield the crude product