E2buteno

E2buteno is not a standard IUPAC name. It most closely corresponds to (E)-but-2-ene, also known as trans-2-butene, the E isomer of the internal alkene with the formula C4H8. The compound exists as two stereoisomers: (E)-but-2-ene (trans) and (Z)-but-2-ene (cis). In the (E) isomer, the higher-priority substituents on each end of the double bond are on opposite sides.

Structure and naming aspect: The molecule is CH3-CH=CH-CH3. The designation E refers to the configuration of the double bond according to CIP priority rules; Z would indicate both higher-priority groups on the same side.

Occurrence and production: Trans-2-butene occurs in small amounts in petroleum fractions and is part of the complex mixture of C4 olefins produced during refining. Industrially, 2-butene is obtained from cracking, isomerization, and refining processes that generate butene isomers. Separation of the E and Z isomers is achieved by distillation or other separation techniques.

Properties: E-2-butene is a colorless, flammable hydrocarbon. It is nonpolar, with low solubility in water and greater solubility in organic solvents. The two stereoisomers have very similar physical properties, with trans-2-butene generally being more thermodynamically stable than its cis counterpart due to reduced steric hindrance.

Reactions and uses: As an internal alkene, it participates in typical addition reactions, such as hydrogenation to butane, halogenation to give dihalides, and epoxidation to form 2,3-epoxybutane. It also serves as a chemical feedstock in the petrochemical industry, providing a source of butene derivatives and enabling various transformations in organic synthesis and refining.

Safety: E-2-butene is flammable and forms potentially explosive mixtures with air. It should be handled in well-ventilated areas away from ignition sources, with appropriate containment and standard laboratory or industrial safety practices. See also trans-2-butene, cis-2-butene, and E/Z isomerism.