Diels-Alder Reactions with o-Quinodimethanes: The influence of protective groups and substituents of allyl alcohols on the stereochemical course—A new access to 18-trifluoroestrans
作者:Hideo Nemoto、Atsushi Satoh、Keiichiro Fukumoto
DOI:10.1016/0040-4020(95)00591-u
日期:1995.9
intramolecular Diels-Alder reaction of the trifluoromethyl substituted olefinic o-quinodimethanes 10, 11, and 21 a – g, generated in situ by the thermolysis of the corresponding benzocyclobutenes 6, 7, and 20a – g respectively, was investigated experimentally and theoretically. The both cis (ring juncture) and anti selectivity [relative configuration of C13 and C17 (steroid numbering) substituents] were enhanced
研究了由相应的苯并环丁烯6、7和20a-g分别热解原位生成的三氟甲基取代的烯烃邻-喹二甲烷10、11和21a-g的分子内Diels-Alder反应的诱导的非对映选择性。实验上和理论上。两个顺式(环接合处)和抗选择性[C的相对构型13和C 17(类固醇编号)取代基]与相应的甲基类似物相比得到了增强。半经验PM3计算已用于定位10、11和21的分子内Diels-Alder反应的过渡结构。将获得的数据与环加成反应的实验结果进行比较,并显示出良好的一致性。