title: Cope rearrangement versus a novel tandem retro-Diels-Alder-Diels-Alder reaction with role reversal.
abstract: [reaction: see text] A reinvestigation of the thermolysis of 4,4-dibromotetracyclo[6.2.1.0(2,7).0(3,5)]undec-9-ene (2) affords diene 8 with a completely rearranged hydrocarbon skeleton via the isolable intermediate 4, along with cyclopentadiene and bromobenzene. DFT calculations show that the novel tandem retro-Diels-Alder-Diels-Alder reaction with role reversal is slightly less favored than the overall single-step Cope rearrangement.
authors.affiliation: Institut für Organische Chemie, Universität Wien, Währinger Strasse 38, A-1090 Wien, Austria.
authors.forename: Kuan-Jen
authors.initials: KJ
authors.lastname: Su
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Mieusset
authors.forename: Vladimir B
authors.initials: VB
authors.lastname: Arion
authors.forename: Lothar
authors.initials: L
authors.lastname: Brecker
authors.forename: Udo H
authors.initials: UH
authors.lastname: Brinker