Tripoli Regis, Cayzer Tory N, Willis Anthony C, Sherburn Michael S, Paddon-Row Michael N
Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia.
Org Biomol Chem. 2007 Aug 21;5(16):2606-16. doi: 10.1039/b708324f.
Intramolecular Diels-Alder reactions of ester-linked 1,3,8-nonatrienes carrying a diphenylcyclopropyl substituent attached to C1 proceed with high levels of stereoselectivity. The stereochemical outcomes of these reactions are explained by reference to B3LYP/6-31G(d) transition structures. Experimentally, the diphenylcyclopropane rings remain intact through these IMDA reactions, notwithstanding their predicted extremely high degree of asynchronicity (the B3LYP-computed lengths in the IMDA transition structures differ by as much as 1.1 angstroms), providing support to the notion that these reactions are concerted processes.
带有连接在C1上的二苯基环丙基取代基的酯连接的1,3,8-壬三烯的分子内狄尔斯-阿尔德反应具有高度的立体选择性。通过参考B3LYP/6-31G(d)过渡结构来解释这些反应的立体化学结果。实验上，尽管预测这些分子内狄尔斯-阿尔德反应具有极高的异步性（在分子内狄尔斯-阿尔德反应过渡结构中，B3LYP计算的键长相差多达1.1埃），二苯基环丙烷环在这些反应中仍保持完整，这为这些反应是协同过程的观点提供了支持。
