96426-55-0Relevant academic research and scientific papers
CYCLOPROPYL CARBANIONS DERIVED FROM ESTERS OF 2-PHENYLCYCLOPROPYLCARBOXYLIC ACIDS: CONFIGURATIONAL STABILITY AND REACTION WITH ELECTROPHILES
Feit, B. A.,Elser, R.,Melamed, U.,Goldberg, I.
, p. 5177 - 5180 (1984)
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-pairs 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 Mel, and the reaction of the cis ester with Ph2C=O, resulted in the corresponding 1-substituted derivatives having cis geometry only.This was explained as due to steric hindrance to electrophilic attack exerted by the 2-phenyl group in the case of the trans substrate.The trans esters did not react with Ph2C=O.Inhibition of the trans-to-cis isomerization of the carbanion salt of the trans substrate in presence of Ph2C=O could lead to this result.
