Thermodynamic Stability of β-Chloro-, β-Phenylthio-, and β-Phenylamino-Substituted α,β and β,γ-Unsaturated Ketones

Abstract

Acid-catalyzed chemical equilibration studies on the titled compounds have been carried out. The β,γ-isomers are highly favored at equilibrium in the cases of β-chloro- and β-phenylthio-substituted ketones. Hydrogen-bonding between carbonyl oxygen and sulfonium or amine proton stabilizes the α,β-unsaturated form.