Toluene → 3-(4'-Chloro-4-ethylbiphen-3-yl)bicyclo[3.2.1]oct-6-ene-2,4-dione

참여 물질

반응 단계

To a solution of 4′-chloro-4-ethylbiphen-3-yllead triacetate (0.478 g, 0.80 mmol) in chloroform (5 ml) is added bicyclo[3.2.1]oct-6-ene-2,4-dione (0.097 g, 0.72 mmol) (preparation described by R. Beaudegnies et al., WO2005/123667) and 4-dimethylaminopyridine (0.36 g, 2.86 mmol), and the reaction mixture is stirred at room temperature for 5 minutes. Next toluene (1 ml) is added, and the mixture is stirred at 80° C. for 2 hours (pre-heated oil bath). The reaction mixture is allowed to cool to room temperature, quenched with 2M hydrochloric acid and the inorganic precipitate removed by filtration. The organic phase is separated, and the aqueous phase is further washed with dichloromethane (×2), and again the phases are separated. All organics are combined then evaporated under reduced pressure to give a brown gum. This crude product is first purified by preparative reverse-phase HPLC, then also by flash column chromatography on silica gel (20% to 100% ethyl acetate/hexane eluant ratio) to afford 3-(4′-chloro-4-ethylbiphen-3-yl)bicyclo[3.2.1]oct-6-ene-2,4-dione.

출처 및 근거