Pericyclic reactions of free and complexed cyclopentyne

Research was conducted to examine the cycloaddition of cyclopentyne with spiro(2.4)hepta-4,6-diene. The objective was to prepare two additional precursors precursors whose decomposition to cyclopentyne could be done without the presence of lithium cations. Results provide strong evidence demonstrating the intervention of lithium-containing complexes when the cycloalkyne is produced through alkyllithium chemistry.