The enol of propionic acid

We demonstrate the gas-phase synthesis of prop-1-ene-1,1-diol, the hitherto unreported higher energy tautomer of propionic acid. The enol was trapped in an argon matrix and characterized by IR and UV/Vis spectroscopy in combination with density functional theory computations. Upon photolysis, the enol rearranges to propionic acid and methylketene. We demonstrate the gas-phase synthesis of prop-1-ene-1,1-diol, the hitherto unreported higher energy tautomer of propionic acid.