2.4-Dinitro-phenylhydrazon d. 2-Oxo-hexen-(5)-ins-(3);2.4-Dinitro-phenylhydrazon d. Hexen-(1)-in-(3)-ons-(5);Hexen-(5)-in-(3)-on-(2)-2.4-dinitro-phenylhydrazon;2.4-Dinitro-phenylhydrazon d. Hexen-(5)-in-(3)-ons-(2);Hex-5-en-3-in-2-on-(2,4-dinitro-phenylhydrazon)