Nucleophilic addition to styryl sulphones. part II. Regio- and stereochemistry of the addition of enamines from 4-substituted cyclohexanones

Formation of β- and α-adducts in the reactions of styryl sulphones with enamines from 4-alkylcyclohexanones is reexamined. Steric effects, electrostatic interactions between the nitrogen atom of the enamine and the oxygen atoms of the sulphone group, and medium effects contribute to the regioselectivity of the reaction.