开环反应即环破裂(ring cleavage)，是闭环反应的逆反应，也包括分子内开环反应和断裂为两个分子的开环反应。
... 开环共聚合：ring-opening copolymerization 开环反应：Ring-opening reaction 开关油：switch oil ...
基于76个网页-相关网页
A new kind of anionic trisiloxane surfactant(ATSS) was synthesized by the ring-opening reaction of maleic anhydride(MA) with hydroxyl terminated polyether group trisiloxane(HPETS). HPETS was prepared by hydrosilylation from 1,1,1,3,5,5,5-heptamethyltrisiloxane(MDHM) and allyl polyoxyethylene ether(APE) in the presence of platinum catalyst.
在铂催化下,1,1,1,3,5,5,5-七甲基三硅氧烷(MDHM)和端烯丙基聚醚(APE)经硅氢加成反应先制得端羟基聚醚三硅氧烷(HPETS),再将其与马来酸酐(MA)进行开环反应合成出一种羧酸型阴离子三硅氧烷表面活性剂(ATSS)。
参考来源 - 阴离子型三硅氧烷表面活性剂的合成及其性能Based on the regioselective acetylation-bromination, unimolecular elimination, epoxidation from pregnanetriol, 16, 17- epoxy-pregn-3S, 20S- diol diacetate was obtained. Then through ring cleavage by Grignard reagent, we got the key intermediate, 16β-methyl-pregn-3, 17, 20-triol in 4 steps with 54% overall yield.
2.以剑麻皂甙元的降解产物孕甾三醇为起始原料,经过区域选择性乙酰化溴代、单消除、环氧化反应得到16, 17-环氧-孕甾-3S, 20S-二醇二乙酸酯,然后经过格氏试剂开环反应以共4步反应,以54%的收率得到关键中间体16β-甲基-孕甾-3, 17, 20-三醇,对β-米松药物中间体Ⅰ的合成也进行了尝试合成研究。
参考来源 - Betamethasone中间体的合成及研究·2,447,543篇论文数据，部分数据来源于NoteExpress
对开环反应机理进行了探讨。
二者的热分解活化能都表明开环反应是速度控制步骤。
Opening ring reaction for two compounds controls the decomposition rate.
结果表明，四种衍生物热分解的主要反应途径都是直接开环反应。
It is discovered that the direct ring rupture channel is the main pathway during the thermal decompositions of the four tetrazole derivatives.
应用推荐