研究了在β环糊精的诱导作用下,丙酮与过氧硫酸氢钾原位产生高效的氧化剂———二甲基二氧杂环丙烷对苯乙烯的不对称环氧化。考察了β环糊精苯乙烯的摩尔比和pH等因素对环氧苯乙烷的产率及对映体过量率的影响。结果表明,水溶液中的β环糊精无论是否溶解,它都能与苯乙烯形成较稳定的包合物,对反应部位产生立体识别作用。在β环糊精底物的摩尔比为31时,提高底物的浓度,可得到更多的产物,光学产率最高可达到29%。 In the presence of β-cyclodextrin, asymmetric epoxidation of styrene with dimethyldioxirane and acetone as oxidant in situ with acetone and potassium peroxodisulfate was studied. The effects of the β-cyclodextrin styrene molar ratio and pH on the yield and enantiomeric excess of styrene oxide were investigated. The results showed that β-cyclodextrin in aqueous solution could form a more stable inclusion complex with styrene, regardless of whether it dissolved or not, resulting in the stereoscopic recognition of the reaction site. In the β-cyclodextrin substrate molar ratio of 31, increasing the concentration of the substrate, you can get more products, optical yield up to 29%.