But-2-ene is an acyclic alkene with four carbon atoms. It is the simplest alkene exhibiting cis/trans-isomerism; that is, it exists as two geometric isomers cis-but-2-ene and trans-but-2-ene.
It is a petrochemical, produced by the catalytic cracking of crude oil or the dimerization of ethylene.
Isomeric forms are 1-butene, cis-2-butene, trans-2-butene, and isobutylene.
The key difference between 1 butene and 2 butene is that 1-butene has a double bond between carbon atoms at the end of the carbon chain, whereas 2-butene has a double bond between carbon atoms at the middle of the compound.
Learn more about 2-butene here:
