Stereoselective synthesis of .alpha.-chloromethylene-.gamma.-butyrolactone derivatives from acyclic allylic 2-alkynoates
作者:Shengming Ma、Xiyan Lu
DOI:10.1021/jo00057a043
日期:1993.2
Alpha-Methylene-gamma-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.