Mass spectrometry of β-ketoesters. Some evidence of their tautomerism

摘要

Mass spectrometric evidence of tautomerism is reported for β-ketoesters. The analysis of the corresponding mass spectra has allowed specific assignment of fragment ions to tautomers. The predictive value of this methodology is supported by the influence of substitution pattern of these compounds on these equilibria. Experimental data are strongly supported by AM1 semiempirical calculations indicating that mass spectrometry could be resourced as a tool for the investigation of tautomerism of neutral species in the gas phase.