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Updated: Dec 31, 2025

Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols
Published on: April 4, 2014
1,1-Ethenediol: The Long Elusive Enol of Acetic Acid
Artur Mardyukov1, André K Eckhardt1, Peter R Schreiner1
1Institute of Organic Chemistry, Justus Liebig University, Heinrich-Buff-Ring 17, 35392, Giessen, Germany.
Abstract:
We present the first spectroscopic identification of hitherto unknown 1,1-ethenediol, the enol tautomer of acetic acid. The title compound was generated in the gas phase through flash vacuum pyrolysis of malonic acid at 400 °C. The pyrolysis products were subsequently trapped in argon matrices at 10 K and characterized spectroscopically by means of IR and UV/Vis spectroscopy together with matching its spectral data with computations at the CCSD(T)/cc-pCVTZ and B3LYP/6-311++G(2d,2p) levels of theory. Upon photolysis at λ=254 nm, the enol rearranges to acetic acid and ketene.
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