Acid-induced rearrangement reactions of reduced benzoquinone cyclopentadiene cycloadducts.
Several Diels-Alder adducts between benzoquinones and cyclopentadiene were reduced to the corresponding diols 7a-c and 11. Treatment of these diols with strong acid triggered a skeletal rearrangement reaction resulting in compounds 8a-c and 12 that contain a 4,8-methanoazulene substructure. In addition, a dyotropic-like rearrangement of the tetracyclic lactone 13 to the spiro-lactone 18 was observed. Five of the structures were supported by X-ray analysis.
Eipert
Martin
M
Universität Tübingen, Institut für Organische Chemie and Institut für Anorganische Chemie, Auf der Morgenstelle 18, D-72076 Tübingen, Germany.
Maichle-Mössmer
Cäcilia
C
Maier
Martin E
ME