含羰基β-环糊精的合成及对苯乙烯的不对称环氧化

Synthesis of containing carbonyl group β-cyclodextrin and stereoselective epoxidation of styrene

由β-环糊精合成单-2-羟丙基-β-环糊精,再利用二氧杂环丙烷氧化成单-2-丙酮基-β-环糊精。以过氧硫酸氢钾复合盐与单-2-丙酮基-β-环糊精产生的二氧杂环丙烷作氧化剂,考察了单-2-丙酮基-β-环糊精与苯乙烯不同物质的量比、NaHCO3用量、过氧硫酸氢钾复合盐用量、以及反应时间和温度等对苯乙烯不对称环氧化的影响。结果表明,单-2-丙酮基-β-环糊精能诱导苯乙烯的不对称环氧化;当反应时间5 h和单-2-丙酮基-β-环糊精、过氧硫酸氢钾复合盐、NaHCO3和苯乙烯的物质的量比为2∶6∶12∶1时,ee值可达到13%。

The mono （2-O-hydroxypropyl） -β-cyclodextrin was synthesized from β-cyclodextrin, and then it was oxided and turned into a β-cyclodextrin-modified ketone by dioxirane. In the presence of oxone, the β-cyclodextrin-modified ketone was used as a supermolecular catalyst for stereoselective epoxidation of styrene. The effects of the molar ratio of the β-cyclodextrin-modified ketone/styrene, the amount of NaHCO3 and oxone, reaction time and temperature on asymmetric epoxidation of the styrene were examined. The experimental results indicated that the 2-O-（prop-2-one-yl）-β-cyclodextrin was a good catalyst to the epoxidation of styrene, when the reaction time was 5 h, the molar ratio of the β-cyclodextrin-modified ketone, oxone, NaHCO3 and styrene was 2： 6： 12： 1, the maximum enantiometric excess of 1,2-epoxyethyl- benzene was up to 13%.