Cyclohexene is a
hydrocarbon with the formula C
6H
10. This
cycloalkene is a colorless
liquid with a sharp smell. It is an intermediate in various industrial processes. Cyclohexene is not very stable upon long term storage with exposure to light and air because it forms
peroxides.
Production and uses
Cyclohexene is produced by the partial
hydrogenation
Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic c ...
of
benzene
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms ...
, a process developed by the
Asahi Chemical
is a multinational Japanese chemical company. Its main products are chemicals and materials science.
It was founded in May 1931, using the paid in capital of Nobeoka Ammonia Fiber Co., Ltd, a Nobeoka, Miyazaki based producer of ammonia, nitri ...
company. In the laboratory, it can be prepared by dehydration of
cyclohexanol.
:
:
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
In chemistry, dehydrogenation is a chemical reaction that involves the removal of hydrogen, usually from an organic molecule. It is the reverse of hydrogenation. Dehydrogenation is important, both as a useful reaction and a serious problem. At ...
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 conformation
In organic chemistry, cyclohexane conformations are any of several three-dimensional shapes adopted by molecules of cyclohexane. Because many compounds feature structurally similar six-membered rings, the structure and dynamics of cyclohexane are ...
al preference for a chair is that it allows each bond of the ring to adopt a
staggered conformation
In organic chemistry, a staggered conformation is a chemical conformation of an ethane-like moiety abcX–Ydef in which the substituents a, b, and c are at the maximum distance from d, e, and f; this requires the torsion angles to be 60°. It ...
. 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-1,3-diene is an organic compound with the formula (C2H4)(CH)4. It is a colorless, flammable liquid. Its refractive index is 1.475 (20 °C, D). A naturally occurring derivative of 1,3-cyclohexadiene is terpinene, a component of pine oi ...
*
Cyclohexa-1,4-diene
External links
*
*
Material Safety Data Sheet for cyclohexene*
ttp://www.orgsyn.org/orgsyn/prep.asp?prep=cv1p0183 Cyclohexene synthesisData sheet at inchem.org
References
{{cycloalkenes
Cycloalkenes
Hydrocarbon solvents
Foul-smelling chemicals