反应详情

To a solution of 1 (7.0 g, 22.7 mmol) in 100 mL of methylene chloride was added 7.5 g of PCC. The mixture was heated to reflux. After 16 hours, the mixture was cooled to room temperature and filtered. The solution was concentrated under reduced pressure. The crude compound was purified by flash chromatography on silica gel (hexane:ethyl acetate=20:1, v/v) to afford the product as a colorless oil. Yield: 3.5 g (50%). 1H NMR (400 MHz, CDCl3) δ 5.06 (m, 2H), 2.66-2.74 (dd, 2H, J=5.64, 16.71 Hz), 2.51-2.60 (dd, 2H, J=7.98, 16.73 Hz), 1.92-2.02 (m, 6H), 1.5-1.67 (s, 6H), 1.58 (s, 6H), 1.19-1.35 (m, 4H), 0.89 (d, 6H, J=6.66 Hz). 13C NMR (400 MHz, CDCl3) δ 200.05, 131.60, 124.07, 52.96, 36.94, 28.49, 25.66, 25.36, 19.71, 17.60.

1. temperatureThe mixture was heated to reflux
2. filtrationfiltered
3. concentrationThe solution was concentrated under reduced pressure
4. customThe crude compound was purified by flash chromatography on silica gel (hexane