Tautomeric Equilibria of 3-Formylacetylacetone: Low-Temperature NMR Spectroscopy and ab Initio Calculations
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- 作者：Eline M. Baslio Janke ; Sebastian Schlund ; Alexander Paasche ; Bernd Engels ; Rdiger Dede ; Ibrar Hussain ; Peter Langer ; Michael Rettig ; Klaus Weisz
- 刊名：Journal of Organic Chemistry
- 出版年：2009
- 出版时间：July 3, 2009
- 年：2009
- 卷：74
- 期：13
- 页码：4878-4881
- 全文大小：145K
- 年卷期：v.74,no.13(July 3, 2009)
- ISSN：1520-6904
文摘
Keto−enol tautomerization of 3-formylacetylacetone has been studied by NMR spectroscopy, ab initio, and DFT calculations in the gas phase and continuum solvation. By employing very low temperatures in a freonic solvent, tautomeric and conformational equilibria in the slow exchange regime were analyzed in detail. The β-tricarbonyl compound always adopts a structure with an enolized keto group irrespective of an increasing dielectric constant of the solvent when lowering the temperature of the Freon mixture. This experimentally observed tautomeric distribution of 3-formylacetylacetone is correctly reproduced by continuum solvated DFT calculations.