Isomer Distribution of Succinylcyclohexenyl, Acetylcyclohexenyl and Acetylcyclopentenyl Enamines

The isomeric distributions of some cyclohexenyl enamines substituted by succinyl or acetyl groups at either the 2- or 6-positions are reported as are the isomeric distributions of similarly substituted cyclopentenyl enamines. Correlation between the 13C NMR chemical shifts in these enamines and isomer distribution is shown. Density functional molecular modeling is used to demonstrate resonance and electrostatic effects on isomeric distributions.