Trans-2-butene is an organic compound with the chemical formula C4H8. It is an alkene, meaning it contains a carbon-carbon double bond. The "trans" designation indicates that the two methyl groups (–CH3) attached to the double-bonded carbons are on opposite sides, which affects its physical properties and reactivity compared to its isomer, cis-2-butene. This compound is commonly used in the production of various chemicals and plastics. It can be found in small amounts in natural gas and is also produced during the refining of petroleum. Trans-2-butene plays a role in organic synthesis and can be converted into other useful compounds through various chemical reactions.