反应详情

To a solution of dione 53 (5.0 g, 18.36 mmol) and chloranil (5.4 g, 22 mmol) in dry ethanol (500 mL) was stirred at 60-65° C. for 2 h. The reaction mixture was concentrated under reduced pressure, and the residue was triturated with dichloromethane. The solid was removed by filtration, and the filtrate was concentrated to give a brown gum. Chromatography (20% EtOAc/hexane) yielded crude dione 54 as a yellow solid (2.3 g, 46%): 1H NMR (300 MHz, CDCl3) δ 0.94 (s, 3, CH3), 5.78 (s, 1), 6.25 (m, 2).

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. customthe residue was triturated with dichloromethane
3. customThe solid was removed by filtration
4. concentrationthe filtrate was concentrated
5. customto give a brown gum