The steric requirements for the synchronous fragmentation of γ-aminohalides as previously postulated have been confirmed by a study of the solvolysis of stereoisomeric 3β- and 3β-chloro-tropanes and -nortropanes. 3β-chloro-tropanes (7 a) and 3β-chloro-nortropane (7 b), which fulfil the stereoelectronic requirements, undergo quantitative fragmentation in 80 vol.% ethanol. They react 1.35 × 104 and 1
通过对立体异构体3β-和3β-
氯代-托环烷和-降
冰片烷的溶剂分解研究,证实了先前假设的γ-
氨基卤化物同步断裂的空间要求。满足立体电子要求的3β-
氯-托烷(7a)和3β-
氯-烷托烷(7b)在80%(体积)的
乙醇中进行定量裂解。它们的反应速度分别为1.35×10 4和1.35×10 3倍,与“同质” exo -3-
氯-
双环[3.2.1]辛烷(12 a)一样快。因此,碎片是通过同步机制发生的。