REACTIONS OF CYCLIC 1,3-DICARBONYL COMPOUNDS WITH ,4)-DIHYDRO-1-METHYL-2(4)-METHYLENE-N-HETEROCYCLES - A NEW ACCESS TO 6,12-METHANO-DIBENZ[D,G]-[1,3]OXAZOCINONES

The enamine-type methylene-N-heterocycles 1-5 react with cyclic 2-etho xymethylene-1,3-dicarbonyl compounds 6 to give 2-[2-(hetarylidene)ethy lidene]-1,3-dicarbonyl compounds 7-14. The result of the reactions bet ween 1,2-dihydro-1-methyl-2-methylene-quinoline (Ia) and cyclic 1,3-di carbonyl compounds depends on the nature of the dihydro intermediates A/B. Dehydrogenation of keton intermediates A results in -(1,2-dimethy l-4(1H)-quinolylidene)-1,3-dicarbonyl compounds 17-21. Enol intermedia tes B with 6-membered dicarbonyl ring form 6,12-methano-dibenz[d,g][1, 3]oxazocinones 22-25. H-1 NM R spectra and X-ray structure analysis pr ove the structure of 23.