Competitive intermolecular pericyclic reactions of free and complexed cyclopentyne.
Intermolecular competition for cyclopentyne by different alkenes supports the hypothesis that organolithium-promoted decomposition of precursors to cyclopentyne affords one or more lithium-ion-complexed species. Competition reactions with mixtures of 2,3-dihydropyran do not clearly differentiate between complexed and unencumbered (free) forms of cyclopentyne, but those involving spirodiene 2 and cyclohexene do. Remarkably, the cycloaddition reactions of free cyclopentyne are not diffusion-controlled despite its high reactivity.
Gilbert
John C
JC
Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station Stop A5300, Austin, Texas 78712, USA. jgilbert@mail.utexas.edu
Hou
Duen-Ren
DR