Degenerate rearrangement of 1-methoxy-1,2-dimethylacenaphthylenonium ion. The inhibiting effect of the acidic medium on the shifts of or groups in carbocations

Abstract

The kinetics of the degenerate rearrangement of 1-methoxy-1,2-dimethylacenaphthylenonium ion in superacidic media with varying acidity were studied by the dynamic1H NMR method. It was concluded that the inhibiting effect of the acidic medium on the migration of the OR groups in the β-OR-substituted carbocations was due not only to protonation of these groups but also to their specific solvation (the formation of hydrogen bonds with the molecules of the medium). Energy estimates of the effect were made for the cases where R=Me and H.