Piperylene or 1,3-pentadiene is an organic compound with the formula CH3−CH=CH−CH=CH2.

It forms a sulfolene upon treatment with sulfur dioxide.

[2] Piperylene is the product of the decarboxylation of sorbic acid, a common anti-mold agent.

[3] Piperylene is obtained as a byproduct of ethylene production from crude oil, combustion of biomass, waste incineration and exhaust gases.

It is used as a monomer in the manufacturing of plastics, adhesives and resins.