Acetals and vinyl ethers of unsaturated aldehydes and ketones in the new syntheses of heterocyclic compounds: XII. New alternatives of acid condensation of cyclohexane-1,4-diones with hydroxyarylaldehydes under dehydration conditions. Fluorecence spectra of the products

1,3-Diethoxy-2-R-5,5-R-1,R-1-1-cyclohexenylium perchlorates in condensation with 2-hydroxyaryl-aldehydes under dehydration conditions give rise to 3-e thoxy-1,2-dihydroxanthylium perchlorates that with the second molecule of 2 -hydroxyarylaldehyde afford 13H-chromeno[3,2-b]xanth-5-ylium perchlorates, and with primary and secondary amines yield 3-(R-2,R-3-amino)-1,2-dihydroxa nthylium perchlorates. The condensation of 2-bromodimedone with salicylalde hydes in triethyl orthoformate and perchloric acid medium furnished 6-bromo -13,13-dimethyl-13H-chromeno[3,2-b]xanth-5-ylium perchlorates. The latter c ompounds show strong fluorescence in 530-630 nm region with 0.48-0.98 quant um efficiency. Under similar conditions the dimedone and 2-acetyldimedone a fford with 2-hydroxyarylaldehydes tris-condensation products: 2,10-dimethox y-6-(3-methoxy-6-oxo-2,4-cyclohexadienylidenemethyl)-7,7-dimethyl-7H-chrome no[2,3-a]-xanth-13-ylium perchlorate and 2,10-dimethoxy-6-(6-methoxychromyl ium-2-yl)-13,13-dimethyl-13H-chromeno[3,2-b]xanth-5-ylium diperchlorate res pectively.