1,5-Hexadiene is the organic compound with the formula (CH2)2(CH=CH2)2.

It is a colorless, volatile liquid.

It is used as a crosslinking agent and precursor to a variety of other compounds.

1,5-Hexadiene is produced commercially by the ethenolysis of 1,5-cyclooctadiene:[1] The catalyst is derived from Re2O7 on alumina.

A laboratory-scale preparation involves reductive coupling of allyl chloride using magnesium:[2]