
Oxidation of cyclotetraveratrylene (CTTV) with potassium permanganate in pyridine under reflux gave tetraketone (the [14]ketonand) 3 which exists as a previously unobserved barrel conformation with S4symmetry in the crystal structure, although the more familiar ‘boat’ conformer was shown by semi-empirical AM1 calculations to be 3.03 kcal/mol lower in energy. In addition to CTTV tetraketone 3, an isomeric bis-spirolactone 4 was isolated from the basic oxidation conditions, analogous to the product of trans-annular attack and rearrangement observed with oxidation of cyclotriveratrylene, whereas in acid at elevated temperatures, tetraketone 3 underwent a very efficient rearrangement and decarboxylation to afford the highly symmetric spirobi[anthracene]-10,10′-dione derivative 5.
© 2012 Taylor & Francis
Available at: http://works.bepress.com/daniel_p_becker/10/
This is an Author's Accepted Manuscript of an article published in Supramolecular Chemistry, Volume 24, Issue 11, 2012 © Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/10610278.2012.719081