Rates and equilibria of keto–enol and –enolate ion interconversion in the 2,4,6-trimethylacetophenone system. Reinvestigation of the unusual bromination reaction

Abstract

The bromination of 2,4,6-trimethylacetophenone, whose unusual kinetics were once thought to be the result of slow, sterically hindered addition of bromine to the enol, was found to be a ring-rather than a side-chain-substitution reaction; kinetic and themodynamic characteristics of this keto–enol system were determined by a combination of flash-photolytic and conventional kinetic techniques and were found to be little different from those of the parent (unsubstituted) acetophenone keto–enol system.