Cyclohexa-1,3-diene is an organic compound with the formula (C2H4)(CH)4.

[2] Conversion of cyclohexa-1,3-diene to benzene + hydrogen is exothermic by about 25 kJ/mol in the gas phase.

[5] Cyclohexadiene and its derivatives form (diene)iron tricarbonyl complexes.

This complex reacts with hydride-abstracting reagents to give the cyclohexadienyl derivative [(C6H7)Fe(CO)3]+.

[7] Cyclohexa-1,3-diene itself is rare in nature, but the cyclohexa-1,3-diene motif is fairly common.