3,4,9,9a-Tetrahydro-1,4-ethano-3,4a-(iminoethano)-4aH-carbazol-2(1H)-one derivatives and N,3-disubstituted 3,3a,4,4a,10,10a-hexahydro-3a-hydroxy-2-oxo-1,9b:4,10-diethanoimidazo[4,5-b]carbazole-5(2H)-carboxamides
3,4,9,9a-Tetrahydro-1,4-ethano-3,4a-(iminoethano)-4aH-carbazol-2(1H)-one derivatives and N,3-disubstituted 3,3a,4,4a,10,10a-hexahydro-3a-hydroxy-2-oxo-1,9b:4,10-diethanoimidazo[4,5-b]carbazole-5(2H)-carboxamides