different steric requirements under refluxing benzene afforded a single stereoisomer of the cyclopropane derivatives 4. The same reaction under refluxing ethanol gave the normal products, i.e. the trans-lactones 6. Mechanism and high stereoselectivity observed in the novel cyelopropane formation, and regiospecific cleavage of the cyclopropane carboxylic acids (in4) have also been discussed in detail
                                    在回流的苯下,具有不同空间要求的碳环的
环氧化物2(ad)的亲核性开环提供了
环丙烷衍
生物4的单一立体异构体。在回流的
乙醇下进行相同的反应,得到正常产物,即反式内酯6。还详细讨论了在新的
环丙烷形成中观察到的机理和高立体选择性,以及
环丙烷羧酸的区域特异性裂解(图4)。