反应详情

To 4.0 g of rac-(1R*,4R*)-bicyclo[2.2.2]octane-2,5-dione (intermediate K1A.1), dissolved in 120 mL of toluene, 1.7 mL of ethylene glycol and 0.27 g of TsOH were added and the solution was heated under vigorous stirring to reflux for 3.5 h. The reaction mixture was cooled to rt, quenched with saturated aq. NaHCO3, extracted with Et2O, and the organic phase was evaporated. The crude product was purified by CC with Hex-EtOAc (7:3) to yield 2.41 g of rac-(1R*,4R*)-spiro[bicyclo[2.2.2]octane-2,2′-[1,3]dioxolan]-5-one as yellow oil.

1. temperaturethe solution was heated
2. temperatureto reflux for 3.5 h
3. customquenched with saturated aq. NaHCO3
4. extractionextracted with Et2O
5. customthe organic phase was evaporated
6. customThe crude product was purified by CC with Hex-EtOAc (7:3)