On the mechanisms of acid-catalyzed enolization and hydrogen isotope exchange of cyclic ketones

The acid-catalyzed hydrogen isotope exchange of norcamphor 1 in DOAc–DCl–D 2 O is shown to follow the general theory (4) for exchange of a diastereotopic proton pair α to a carbonyl group. That is, the less reactive proton undergoes exchange via two channels. Through an analysis of a combination of the rate data for acid-catalyzed bromination and the pK BH+ values for a series of cyclic and bicyclic ketones, we establish that the reactivity …