C 73 Condensation of 2-polyfluoroacycloalkanones with aldehydes and dimethylformamide-dimethylacetal [Text] / D. V. Sevenard, O. G. Khomutov, M. I. Kodess, K. I. Pashkevich, I. Loop, E. Lork, G. -V. Roeschenthaler // Australian Journal of Chemistry. - 2001. - Vol. 54, № 3. - P157-163 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Polyfluorinated 1,3-diketones containing carbocycles react with aldehydes under Lewis-acid catalysis and also with dimethylformamide-dimetylacetal without catalysis, yielding exclusively (E)-configured condensation products involving the methylene group of the carbocycle. Novel trifluoromethylated chromenes are prepared from 2-trifluoroacetylcycloalkanones and salicylaldehyde. The structures of two new compounds, 2-(E)-benzylidene-6-trifluoroacetylcyclohexanone and 4-trifluoroacetyl-2,3-dihydro-1H-xantene, are confirmed by X-ray structure analysis. |