4,10,11,11-tetramethyl-8-phenyl-2-oxa-3,8,9-triaza-dispiro[4.0.4.1]undeca-3,9-diene-1,7-dione
2,2,7-trimethyl-4-oxo-5-oxa-6-aza-spiro[2.4]hept-6-ene-1,1-dicarbonitrile
4-[3-(4-dimethylamino-phenyl)-1-methyl-allylidene]-3-methyl-4H-isoxazol-5-one
2,4-dimethyl-1H-pyrrole
2,5-Dimethylpyrrole