Chemistry of Bridged Aromatics. A Study of the Substituent Effect on the Course of Bond Cleavage of 9,10-Dihydro-9,10-ethanoanthracenes and an Oxyanion-Assisted Retro-Diels-Alder Reaction

Article abstract of DOI:10.1021/jo00153a006

The retro-Diels-Alder reactions of 9,10-dihydro- and 1,4,9,10-tetrahydro-9,10-ethanoanthracenes are dramatically accelerated by an oxyanion substitution on the 2? component, i.e., the ethano bridge.Studies of related systems bearing anionic, cationic, and radical substituents indicate that the cycloreversion is concerted and occurs only if both 4? and 2? fragments are highly resonance stabilized.