反应详情

Ozone was bubbled into a solution of 21-3 (1.5 g, 6.4 mmol) in 2:1 CH3OH/CH2Cl2 (102 mL) at -78° C. After 5 min no starting material remained so oxygen was bubbled through the solution for 15 min to remove excess ozone. NaBH4 (1.7 g, 45 mmol) was added and the cooling bath removed. After 1 h the reaction mixture was concentrated. The residue was diluted with H2O (30 mL) and then extracted with CHCl3 (300 mL). The organic phase was washed with brine (30 mL), dried (MgSO4), and concentrated. Flash chromatography (silica, EtOAc) gave 21-4 as a nearly colorless oil. Rf 0.42 (silica, EtOAc).

1. customoxygen was bubbled through the solution for 15 min
2. customto remove excess ozone
3. customthe cooling bath removed
4. concentrationAfter 1 h the reaction mixture was concentrated
5. additionThe residue was diluted with H2O (30 mL)
6. extractionextracted with CHCl3 (300 mL)
7. washThe organic phase was washed with brine (30 mL)
8. dry with materialdried (MgSO4)
9. concentrationconcentrated
10. customFlash chromatography (silica, EtOAc) gave 21-4 as a nearly colorless oil