反应详情

To a 100 mL three-neck round bottom flask, were added buffer (0.05 M Na2B4O7.10H2O in 4×10−4 M aq. Na2EDTA, 10 mL), acetonitrile (15 mL), trans-β-methylstyrene (0.118 g, 1 mmol), tetrabutylammonium hydrogen sulfate (0.015 g, 0.04 mmol), and ketone 1 (0.0774 g, 0.3 mmol). The reaction mixture was cooled by an ice bath. A solution of Oxone® (0.85 g, 1.38 mmol) in aq. Na2EDTA (4×10−4 M, 6.5 mL) and a solution of K2CO3 (0.8 g, 5.8 mmol) in water (6.5 mL) were added dropwise through two separate addition funnels over a period of 1.5 h (under this condition, the reaction pH is around 10.5. It is recommended that both Oxone® and K2CO3 be added uniformly over 1.5 h). At this point, the reaction was immediately quenched by addition of pentane and water. The mixture was extracted with pentane (3×30 mL), washed with brine, dried over Na2SO4, purified by flash chromatography [the silica gel was buffered with 1% Et3N in pentane, pentane/ether (1/0 to 50/1, V/V) was used as eluent] to afford trans-β-methylstyrene oxide as colorless liquid (0.124 g, 93 yield, 92%ee).

1. temperatureThe reaction mixture was cooled by an ice bath
2. customseparate
3. additionaddition funnels over a period of 1.5 h (under this condition
4. customthe reaction pH is around 10.5
5. additionbe added uniformly over 1.5 h)
6. customAt this point, the reaction was immediately quenched by addition of pentane and water
7. extractionThe mixture was extracted with pentane (3×30 mL)
8. washwashed with brine
9. dry with materialdried over Na2SO4
10. custompurified by flash chromatography [the silica gel
11. customto afford