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.