Cyclooctane is a

cycloalkane In organic chemistry, the cycloalkanes (also called naphthenes, but distinct from naphthalene) are the ring (chemistry), monocyclic Saturated and unsaturated compounds, saturated hydrocarbons. In other words, a cycloalkane consists only of hydroge ...

with the

molecular formula A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as paren ...

(CH₂)₈. It is a simple colourless

hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and Hydrophobe, hydrophobic; their odor is usually fain ...

, but it is often a reference compound for saturated eight-membered ring compounds in general. Cyclooctane has a

camphor Camphor () is a waxy, colorless solid with a strong aroma. It is classified as a terpenoid and a cyclic ketone. It is found in the wood of the camphor laurel (''Cinnamomum camphora''), a large evergreen tree found in East Asia; and in the kapu ...

aceous odor.

Conformations

The conformation of cyclooctane has been studied extensively using

computational A computation is any type of arithmetic or non-arithmetic calculation that is well-defined. Common examples of computation are mathematical equation solving and the execution of computer algorithms. Mechanical or electronic devices (or, historic ...

methods. Hendrickson noted that "cyclooctane is unquestionably the conformationally most complex cycloalkane owing to the existence of many conformers of comparable energy". The boat-chair conformation (below) is the most stable form. Allinger and co-workers confirmed this. The crown conformation (below) is slightly less stable. Among the many compounds exhibiting the crown conformation (structure II) is S₈, elemental

sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...

. :

Synthesis and reactions

The main route to cyclooctane derivatives involves the dimerization of

butadiene 1,3-Butadiene () is the organic compound with the formula CH2=CH-CH=CH2. It is a colorless gas that is easily condensed to a liquid. It is important industrially as a precursor to synthetic rubber. The molecule can be viewed as the union of two ...

, catalysed by nickel(0) complexes such as nickel bis(cyclooctadiene). This process affords, among other products,

1,5-cyclooctadiene 1,5-Cyclooctadiene (also known as cycloocta-1,5-diene) is a cyclic compound, cyclic hydrocarbon with the chemical formula , specifically . There are three configurational isomers with this structure, that differ by the arrangement of the four C� ...

(COD), which can be hydrogenated. COD is widely used for the preparation of precatalysts for

homogeneous catalysis In chemistry, homogeneous catalysis is catalysis where the catalyst is in same phase as reactants, principally by a soluble catalyst in a solution. In contrast, heterogeneous catalysis describes processes where the catalysts and substrate are in d ...

. The activation of these catalysts under H₂, produces cyclooctane, which is usually discarded or burnt: :C₈H₁₂ + 2 H₂ → C₈H₁₆ Cyclooctane participates in no reactions except those typical of other saturated hydrocarbons,

combustion Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion ...

and

free radical halogenation In organic chemistry, free-radical halogenation is a type of halogenation. This chemical reaction is typical of alkanes and alkyl-substituted aromatics under application of UV light. The reaction is used for the industrial synthesis of chloroform ...

. Work in 2009 on alkane functionalisation, using peroxides such as dicumyl peroxide, has opened up the chemistry to some extent, allowing for example the introduction of a phenylamino group. : CyclooctaneAmination

References

{{Authority control Cycloalkanes Hydrocarbon solvents Eight-membered rings