R. Sigrist, H. Hansen
Aug 1, 2010
Citations
0
Influential Citations
2
Citations
Journal
Helvetica Chimica Acta
Abstract
The 1-(3-methylazulen-1-yl)alkan-1-ones, when oxidized with excess 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (=4,5-dichloro-3,6-dioxocyclohexa-1,4-diene-1,2-dicarbonitrile; DDQ) in aqueous acetone in the presence of 1-(3-demethylazulen-1-yl)alkan-1-ones, form the corresponding unsymmetrically substituted bis(3-acylazulen-1-yl)methanones in good to excellent yields (Schemes 4, 5, 7, and 10). Intermediates are the corresponding disubstituted methane derivatives, which are formed by radical and radical-cation recombination (Scheme 6). The 1-(3-methylazulen-1-yl)alkan-1-ones can as well be coupled oxidatively with azulene itself, benz[a]azulene, or 1,3-dimethoxybenzene (Schemes 9–11).