A stable enol from a 6-substituted benzanthrone and its unexpected behaviour under acidic conditions

• Published in: Beilstein journal of organic chemistry Vol. 5; no. 1; p. 31
• Main Authors: Debeaux, Marc, Brandhorst, Kai, Jones, Peter G, Hopf, Henning, Grunenberg, Jörg, Kowalsky, Wolfgang, Johannes, Hans-Hermann
• Format: Journal Article
• Language: English
• Published: Germany Beilstein-Institut 16.06.2009
• Subjects: Chemistry; consecutive reactions; Full Research Paper; intramolecular cyclization; molecular modelling; spiro compounds; X-ray structural analysis; X-ray structural analysis; consecutive reactions; intramolecular cyclization; spiro compounds; molecular modelling

Treatment of benzanthrone (1) with biphenyl-2-yl lithium leads to the surprisingly stable enol 4, which is converted by dehydrogenation into the benzanthrone derivative 7. Under acidic conditions 4 isomerises to the spiro compound 11 and the bicyclo[4.3.1]decane derivative 12. Furthermore, the forma...