ADDITION OF ALPHA-KETOENAMINES TO 2-ACETYL-P-BENZOQUINONE

Addition of 2-morpholino-2-cyclohex-1-en-one 2 to 2-acetyl-quinone 1 y ields benzo[c][4H]chro-men-4,7,10-trion 4 which is unstable and rearra nges to 5. 4 is converted to dihydroxy-phenyl)-2-mor-pholino-2-cyclohe x-1-en-on 3 thermically and to dibenzo[b,d]furan-4-on 7 acid catalyzed . The structure of 7 is secured by independent synthesis. Dibenzo[b,d] furan-4-on 14 is the product of reaction from 2-(p-toluidino)-2-cycloh ex-1-en-on 9 and 1 with benzo [c] [4H] chromen-4,7, 10-trion 10 as int ermediate. By proton catalysis 5-acetyl-6-hydroxy-carbazol-1-on 13 and 4-oxo-cyclohexa[c]isochinolinium hydrochlorid 15 is obtained from 10. 1H-cyclopenta[d]furan-3-on 17 is formed by addition of 2-(p-toluidino )-2-cyclo-pent-1-en-on 16 to 1. It is rearranged by proton catalysis t o 3-oxo-1 H-cyclopenta[c]isochinolinium salt 18. Reaction of cyclopent an-1,2-dione and 1 yields 3 aH-cyclopenta[c]isochromen-3,6,9-trion 20, rearranging to 1H-cyclopenta[b]benzo[d]furan-3-on 21. The s stereoche mistry of adducts is discussed in connection with the course of the re action, spectroscopical evidence, molecular modelling and calculation of HOMO/LUMO and AO-coefficients.