Reactions of Cyclic 1,3-Dicarbonyl Compounds with 1,2(1,4)-Dihydro-1-methyl-2(4)-methylene-N-heterocycles. A New Access to 6,12-Methano-dibenz-oxazocinones

Article abstract of DOI:10.1007/BF00811679

The enamine-type methylene-N-heterocycles 1-5 react with cyclic 2-ethoxymethylene-1,3-dicarbonyl compounds 6 to give 2-<2-(hetarylidene)ethylidene>-1,3-dicarbonyl componds 7-14.The result of the reactions between 1,2-dihydro-1-methyl-2-methylene-quinoline (1a) and cyclic 1,3-dicarbonyl compounds depends on the nature of the dihydro intermediates A/B.Dehydrogenation of keton intermediates A results in 2-(1,2-dimethyl-4(1H)-quinolylidene)-1,3-dicarbonyl compounds 17-21.Enol intermediates B with 6-membered dicarbonyl ring form 6,12-methano-dibenz<1,3>oxazocinones 22-25. 1H NMR spectra and X-ray structure analysis prove the structure of 23. - Keywords. 2-<2-(Hetarylidene)ethylidene>-1,3-dicarbonyl compounds; 2-(1,2-Dimethyl-4(1H)-quinolylidene)-1,3-dicarbonyl compounds; 6,12-Methano-dibenz<1,3>oxazocinones; X-ray analysis.