Carbolithiation for the generation of cyclooctadienyl anions and tandem electrocyclization/alkylation to functionalized cis-bicyclo[3.3.0]octenes.

A powerful cascade reaction process for the construction of functionalized cis-bicyclo[3.3.0]octenes has been developed. Carbolithiation of 3-methylene-1,4-cyclooctadiene with 1 degrees , 2 degrees , or 3 degrees alkyllithium reagents leads to cyclooctadienyl anions, which undergo disrotatory electrocyclization and subsequent trapping with carbon, oxygen, sulfur, or silicon electrophiles to provide functionalized cis-bicyclo[3.3.0]octenes. Transmetalation of the allyllithium intermediates allowed access to the cuprate manifold of reactivity. The rapid construction of a linear triquinane using this methodology demonstrates the potential for synthetic applications.