SUR LES PRÉSUMÉS cis-DIHALOGÉNURES DE QUINONES

Abstract

It has been proposed, mainly on the basis of spectral evidence, that the addition of chlorine to p-benzoquinone gives the cis-dichloride, and that in an alcoholic solution this substance isomerizes to the trans-dichloride, which then enolizes to the corresponding hydroquinone. Upon reexamination of the evidence and isolation of the intermediates and end products of the reaction in an alcoholic solution, it can now be reasserted that the trans-dichloride is the only detectable isomer resulting from chlorination under various conditions. The observed changes in an alcoholic solution have been proven to be the result of elimination followed by photochemical reduction. Similar conclusions have been reached in the case of quinone dibromides.