[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([C:8](=[CH2:12])[CH:9]([OH:11])[CH3:10])=[CH:4][CH:3]=1>C(Cl)Cl.[O-2].[O-2].[Mn+4]>[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([C:8](=[CH2:12])[C:9](=[O:11])[CH3:10])=[CH:4][CH:3]=12.91 g of alcohol 39 is dissolved in 300 ml of methylene chloride, and 43.5 g of manganese dioxide is added under nitrogen. It is stirred overnight at room temperature, filtered on Celite, and the residue is chromatographed on silica gel with ethyl acetate/hexane, whereby 850 mg of title compound 40 in addition to 1.06 g of the starting material are obtained as colorless oils.
Loading…