Enantioselective synthesis of oxiranes by the reactions of dimethylsulfonium methylide and aromatic aldehydes and ketones in the presence of chiral micelles

Within chiral micelles formed from chiral surfactants N-dodecyl-N,N-dimethyl ephedrine bromide I and N-hexadecyl-N, N-dimethyl ephedrine bromide II, a series of optically active products was obtained by the reactions of dimethylsulfonium methylide and aromatic aldehydes, ketones. The highest ee was up to 57.2%. Meanwhile, we have found that the asymmetric induction depends on a number of factors, such as the alkyl chain length of surfactant, reaction temperature, reaction time and the concentration of base in aqueous micellar solution. (C) 1997 Elsevier Science Ltd.