Reaction of Cyclohexanone Benzylimines with Ethylidenemalonate Diesters. Diphenyl 2-Ethylidenemalonate: A Highly Electrophilic Synthetic Equivalent of Crotonic Esters
作者:Ivan Jabin、Gilbert Revial、Nicolas Monnier-Benoit、Pierre Netchitaïlo
DOI:10.1021/jo005657h
日期:2001.1.1
Michael alkylation of alpha-substituted and alpha,alpha'-disubstituted cyclohexanone benzylimines with ethylidenemalonate diesters was carried out for mechanistic and synthetic purposes. In the first case, an inverse regioselectivity occurred in comparison with what is generally observed since the Michael adducts resulted from alkylation of the non substituted enamine tautomer. With alpha,alpha'-disubstituted
为了机理和合成目的,进行了α-取代的和α,α′-二取代的环己酮苄基亚胺与亚乙基丙二酸酯二酯的非对映选择性迈克尔烷基化。在第一种情况下,由于迈克尔加合物是由未取代的烯胺互变异构体的烷基化产生的,因此与通常观察到的相比,发生了逆区域选择性。在所有情况下,对于α,α′-二取代的亚胺,主要的非对映异构体的立体化学是从一种机制中预期到的,该机制包括椅子样复合物方法,其中亚乙基丙二酸二酯的β-甲基具有优选的exo位置。此外,发现2-亚乙基丙二酸二苯基酯4是巴豆酸酯的高度亲电子的合成等同物。