Cyclohexene

Cyclohexene is a hydrocarbon with the formula (CH₂)₄C₂H₂. It is an example of a cycloalkene. At room temperature, cyclohexene is a colorless liquid with a sharp odor. It has few practical applications.

Production and uses

Cyclohexene is produced by the partial hydrogenation of benzene, a process developed by the Asahi Chemical company. The main product of the process is cyclohexane because cyclohexene is more easily hydrogenated than benzene.

In the laboratory, it can be prepared by dehydration of cyclohexanol.

C₆H₁₁OH → C₆H₁₀ + H₂O

Reactions and uses

Benzene is converted to cyclohexylbenzene by acid-catalyzed alkylation with cyclohexene. Cyclohexylbenzene is a precursor to both phenol and cyclohexanone.

Hydration of cyclohexene gives cyclohexanol, which can be dehydrogenated to give cyclohexanone, a precursor to caprolactam.

The oxidative cleavage of cyclohexene gives adipic acid. Hydrogen peroxide is used as the oxidant in the presence of a tungsten catalyst.

Bromination gives 1,2-dibromocyclohexane.

Structure

Cyclohexene is most stable in a half-chair conformation, unlike the preference for a chair form of cyclohexane. One basis for the cyclohexane conformational preference for a chair is that it allows each bond of the ring to adopt a staggered conformation. For cyclohexene, however, the alkene is planar, equivalent to an eclipsed conformation at that bond.

See also

• Diels-Alder reaction
• Cyclohexa-1,3-diene
• Cyclohexa-1,4-diene

References

External links

• International Chemical Safety Card 1054
• NIOSH Pocket Guide to Chemical Hazards. "#0167". National Institute for Occupational Safety and Health (NIOSH).
• Material Safety Data Sheet for cyclohexene
• Safety MSDS data
• Reaction of Cyclohexene with Bromine and Potassium Permanganate
• Cyclohexene synthesis
• Data sheet at inchem.org