Bifunctional catalysis of the enolization of acetone

The third-order term for acid--base catalysis of acetone enolization was found to exhibit a Bronsted β/sub AB/ value of 0.15, a solvent isotope effect of k/sub H2O//k/D2O/ = 2.0, and a C--H isotope effect of k/sub H//k/sub D/ = 5.8. It is concluded that this reaction represents true bifunctional catalysis with partial proton abstraction by acetate ion and a significant movement of the proton of acetic acid toward the carbonyl oxygen atom in the transition state