Separation of keto–enol tautomers in β-ketoesters: a gas chromatography–mass spectrometric study

Abstract The gas chromatographic behaviour for some β-ketoesters was studied. Additionally, the feasibility of the gas chromatographic separation of the corresponding tautomer forms was examined. In this work mass spectrometric detection allowed identification of both keto and enol forms and an estimation of their relative amounts for methylacetoacetate, α-chloromethylacetoacetate, ethylacetoacetate and α-chloroethylacetoacetate. This finding demonstrates slow tautomerisation kinetics permitting the chemical identity maintenance of the tautomers.