The Chemistry of Aryllead(IV) Tricarboxylates. Reaction with Phenols

Abstract

A mixture of mesitol (l), p-methoxyphenyllead triacetate (2) and pyridine in equimolar quantities in chloroform gives an almost quantitative yield of the 6-arylcyclohexa-2,4-dienone (3) and the 4-aryl-cyclohexa-2,5-dienone (4) in a ratio of 4 : 1. Examination of the effect of substituents on the reaction has shown that with methylated phenols it only proceeds in high yield when both ortho positions are substituted, while the reaction fails with phenols bearing only electron-withdrawing groups. There is a marked preference for ortho arylation and a preference for attack ipso to a methoxyl group compared with methyl groups. 2-Methyl-1-naphthol was the only polynuclear phenol examined, and it reacted in the expected manner to give the 2-arylnaphthalen-1(2H)-one (24).