The chemistry of aryl-lead(IV) tricarboxylates. Reaction with vinylogous β-keto esters

Abstract

A study of the arylation of ethyl 4-oxocyclohex-2-enecarboxylate and a number of its derivatives by aryl-lead triacetates has been carried out. Ethyl 2-methyl-4-oxocyclohex-2-enecarboxylate (Hagemann's ester)(7), and ethyl 4-oxocyclohex-2-enecarboxylate (10a) and its double bond isomer (10b) were found to undergo regiospecific arylation at C-1 in good yield, whereas the compounds (14) and (16), which have C-3 substituents, gave low yields of products resulting from arylation at both C-1 and C-3. The latter behaviour was also displayed by the isomers (20a) and (20b), which contain a 6-methyl substituent.