Organocuprate Reactions with Cyclopropanes. Evidence for Three Types of Mechanism

Article abstract of DOI:10.1021/jo00184a015

Cyclopropane ring openings by organocuprates can be classified into three distinct classes.Mechanistically, the simplest openings are the direct nucleophilic displacements with enolate leaving groups.In order to be synthetically useful, these reactions usually require activation by two groups.Substrates that contain vicinal olefin and activating groups generally are opened by S_N2'-like displacements.Finally, β-cyclopropyl-α,β-unsaturated ketones react by a mechanism intimately related to the conjugate addition reaction of α,β-unsaturated ketones.