反应详情

To 2.37 g (9.05 mmol) of alcohol 19 in 18 mL of CH2Cl2 was added 7.86 g (90.45 mmol) of MnO2. The reaction mixture was stirred for 3 h, then filtered (celite over silica gel pad) and the pad was washed repeatedly with 20 mL aliquots of CH2Cl2. After concentration, ketone 20 was purified by chromatography (SiO2, 3% EtOAc-hexanes) to give 941 mg (3.62 mmol) of 20 (40% yield): TLC (10% EtOAc-90% hexanes) Rf 0.7; 1H-NMR (CDCl3)δ 1.01 (t, 3H, CH2CH3), 1.34 (s, 18H, 6(CH3)), 1.78 (m, 2H, CH2CH3), 2.96 (t, J=7 Hz, 2H, CH2CH2CH3), 7.63 (t, J=1 Hz, 1H, Ar--H), 7.83 (d, J=1 Hz, 2H, Ar--H).

1. filtrationfiltered (celite over silica gel pad)
2. washthe pad was washed repeatedly with 20 mL aliquots of CH2Cl2
3. concentrationAfter concentration, ketone 20
4. customwas purified by chromatography (SiO2, 3% EtOAc-hexanes)