反应详情

To a solution of oxazole alcohol 3 (9.9 g, 64 mmol) in acetone (200 mL, Aldrich, Cat. No. 179124) was added MnO2 (27.7 g, 319 mmol, 5 equiv., Wako Pure Chemical, Osaka, Japan, Cat. No. 138-09675), and the mixture was stirred at room temperature overnight. After celite filtration to remove MnO2, the solvent was removed by evaporation, and the residual pale brown oil was dissolved in CHCl3 and applied to silica-gel column chromatography (prepared with CHCl3), then eluted with CHCl3:MeOH (100:1 to 50:1), to give an pale yellow oil of aldehyde 4 (5.54 g, 57% (38% in two steps)). Rf 0.65 (CHCl3:MeOH=10:0.5), 1H NMR (300 MHz CDCl3) δ 10.10 (s, 1H), 7.77 (s, 1H), 1.47 (s, 9H); HRMS(EI): m/z 153.0794 (M+) (Calcd for C8H11NO2: 153.0790).

1. filtrationAfter celite filtration
2. customto remove MnO2
3. customthe solvent was removed by evaporation
4. dissolutionthe residual pale brown oil was dissolved in CHCl3
5. customapplied to silica-gel column chromatography (prepared with CHCl3)
6. washeluted with CHCl3:MeOH (100:1 to 50:1)