Reactions of β-keto-enol ethers with bromine in aqueous solution

Abstract

The β-keto-enol ethers acetylacetone enol methyl ether, dimedone enol methyl ether, and 2,3-dihydro-2,6-dimethyl-γ-pyrone undergo fast olefinic addition reactions with aqueous bromine. Rate measurements for the last two are correlated with published data for olefins and enols. The bromination products of the first two, but not those of the last one, undergo slow, acid-catalysed fission of the méthoxy-group to give the bromo-enol.