Acetonitrile → (1S,2S)-(-)-1-Phenylpropylene oxide

Beteiligte Stoffe

Reaktionsschritte

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).

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