作者:John E. Davies、Ian Fleming、Jonathan M. Goodman
DOI:10.1039/b309329h
日期:——
The bicycloheptene 6 rearranged in acid to give the tricycloheptane 9, as shown by an X-ray crystal structure determination of the p-nitrobenzoate 10 derived from it. Earlier results in the literature had already indicated that this isomer was the thermodynamic sink. This apparently crowded structure, with its three contiguous quaternary centres, is, nevertheless, lower in energy than other accessible but less crowded structures, because of electronic stabilisation of the more substituted cyclopropane ring conjugated to the ester group.
双环庚烯 6 在酸中重新排列,得到三环庚烷 9,由它衍生出的对硝基苯甲酸酯 10 的 X 射线晶体结构测定结果表明了这一点。早先的文献研究结果已经表明,这种异构体是热力学沉降物。然而,由于与酯基共轭的取代程度较高的环丙烷环的电子稳定作用,这种具有三个相邻季中心的明显拥挤结构的能量低于其他可获得但不那么拥挤的结构。