反应详情

A solution of the regioisomers 21 (0.77 g, 2.69 mmol) in dichloromethane (10 mL) was treated with manganese dioxide (0.94 g, 10.77 mmol). The resulting mixture was stirred at room temperature for 2 h. The reaction mixture was filtered through Celite and concentrated. The crude product was purified by silica gel chromatography (0-5% methanol/CH2Cl2) to afford 0.24 g (31% yield) of 22 as a single regioisomer: 1H NMR (400 MHz, CDCl3) δ 10.08 (s, 1H), 8.34 (s, 1H), 7.85-7.65 (m, 4H), 4.45 (t, J=12.0 Hz, 2H), 3.77-3.71 (m, 2H), 2.42-2.34 (m, 2H); ESI+ MS: m/z (rel intensity) 285.0 (100, [M+H]+).

1. filtrationThe reaction mixture was filtered through Celite
2. concentrationconcentrated
3. customThe crude product was purified by silica gel chromatography (0-5% methanol/CH2Cl2)