Stereoselective Synthesis of α-(Chloromethylene)-γ-butyrolactone Derivatives from Acyclic Allylic 2-Alkynoates

Article abstract of DOI:10.1021/jo00057a043

α-Methylene-γ-butyrolactones have been constructed by a bis(benzonitrile)palladium dichloride catalyzed cyclization reaction of the easily available acyclic 2'-alkenyl 2-alkynoates in the presence of CuCl2.A mechanism involving a stereoselective chloropalladation in the presence of CuCl2, followed by intramolecular insertion of a carbon-carbon double bond to the carbon-palladium bond, and subsequent CuCl2-mediated formation of a new carbon-chlorine bond is briefly discussed.