反应详情

A solution of pyridine (1.8 mL) in 28 mL of CH2Cl2 was cooled in an ice bath and chromium trioxide (1.12 g) was added in one portion. The mixture was stirred at the same temperature for 20 min and at room temperature for 1 h. A solution of 67 (300 mg) in 2 mL of CH2Cl2 was added in one portion and the mixture was stirred for 1 h at room temperature. It was filtered through a pad of silica gel (5 g) and rinsed through with 50 mL of ethyl acetate. The filtrate was concentrated in vacuo to give the crude aldehyde which was used without further purification. 1H NMR (400 MHz, CDCl3) δ 0.93 (t, J=7.4 Hz, 3H), 1.38 (sextet, J=7.4 Hz, 2H), 1.61 (pentet, J=7.1 Hz, 2H), 4.09 (t, J=6.7 Hz, 2H), 4.14 (d, J=5.0 Hz, 2H), 5.30 (broad s, 1H), 9.66 (s, 1H).

1. stirringthe mixture was stirred for 1 h at room temperature
2. filtrationIt was filtered through a pad of silica gel (5 g)
3. washrinsed through with 50 mL of ethyl acetate
4. concentrationThe filtrate was concentrated in vacuo