Cyclopropyl carbanions derived from esters of 2-phenylcyclopropylcarboxylic acids: Configurational stability and reaction with electrophiles
作者:B.A. Feit、R. Elser、U. Melamed、I. Goldberg
DOI:10.1016/s0040-4020(01)91267-0
日期:1984.1
The base-catalyzed cis-trans isomerization of cis and trans-alkyl 2-phenylcyclopropylcarboxylates was studied in several aprotic solvents. It was found that contact ion-pain of the derived carbanion lithium salts were configurationally more stable than the solvent-separated ones. Reaction of either the cis or the trans esters with MeI, and the reaction of the cis ester with Ph2C = O, resulted in the
在几种非质子溶剂中研究了碱催化的顺式和反式2-苯基环丙基羧酸酯的顺式和反式异构化。发现衍生的碳负离子锂盐的接触离子疼痛在结构上比溶剂分离的更稳定。任一的反应顺式或反式用MeI酯,以及所述的反应顺式的Ph酯2 C = O,导致在相应的具有I -取代的衍生物的顺式仅几何。这被解释为是由于在反式底物的情况下对2-苯基施加的亲电子进攻的空间位阻。该反式酯不与Ph 2 C = O反应。所述的抑制反式-到-顺式的的负碳离子盐的异构化反pH值的存在基板2 C = O可能导致这样的结果。