Highly Enantiospecific Platinum-Catalyzed Cycloisomerizations: Synthesis of Enantioenriched Oxabicycloheptene Derivatives

Enantiospecific cycloisomerizations of 1,6-enynes to form oxabicyclo[4.1.0]heptene derivatives are described. Enantiospecificity is consistently high regardless of alkene or alkyne substitution, providing a general approach to greatly enantioenriched cyclopropanes. Additionally, a model for stereochemical transfer is proposed.