Hydrogen Peroxide → (1S,2S)-(-)-1-Phenylpropylene oxide

Beteiligte Stoffe

Reaktionsschritte

Unlike CF3COCH3, which gives higher conversion at high pH, acetone catalyzed epoxidation reactions proceeded at much faster rate at a lower pH (about 8.3). Because the decomposition of H2O2 was not very fast at this pH, the reaction can be done at room temperature. Although controlled experiment showed that significant amount of epoxidation also occurred in the absence of acetone at this pH (Payne epoxidation), the addition of acetone allowed the epoxidation to proceed much faster and gave higher conversion. For example, a 41% conversion of trans-β-methylstyrene was obtained in the absence of acetone after stirred at room temperature for 10 h. However, in the presence of acetone, an 83% yield of trans-β-methylstyrene oxide could be obtained after stirring for 5 h. Table 4 lists additional examples using acetone under similar conditions.

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