Copaene, or more precisely, α-copaene, is the common (or trivial) chemical name of an oily liquid hydrocarbon

Hydrocarbon

In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....

 that is found in a number of essential oil-producing plants. The name is derived from that of the resin

Resin

Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...

-producing tropical copaiba

Copaiba

Copaiba is a stimulant oleoresin obtained from the trunk of several pinnate-leaved South American leguminous trees . The thick, transparent exudate varies in color from light gold to dark brown, depending on the ratio of resin to essential oil...

 tree, Copaifera langsdorfii, from which the compound was first isolated in 1914. Its structure, including the chirality

Chirality (chemistry)

A chiral molecule is a type of molecule that lacks an internal plane of symmetry and thus has a non-superimposable mirror image. The feature that is most often the cause of chirality in molecules is the presence of an asymmetric carbon atom....

, was determined in 1963. The double-bond isomer with an exo-methylene group, β-copaene, was first reported in 1967.

Chemically, the copaenes are tricyclic sesquiterpenes

Terpene

Terpenes are a large and diverse class of organic compounds, produced by a variety of plants, particularly conifers, though also by some insects such as termites or swallowtail butterflies, which emit terpenes from their osmeterium. They are often strong smelling and thus may have had a protective...

. The molecules are chiral, and the α-copaene enantiomer

Enantiomer

In chemistry, an enantiomer is one of two stereoisomers that are mirror images of each other that are non-superposable , much as one's left and right hands are the same except for opposite orientation. It can be clearly understood if you try to place your hands one over the other without...

 most commonly found in higher plants exhibits a negative optical rotation

Optical rotation

Optical rotation is the turning of the plane of linearly polarized light about the direction of motion as the light travels through certain materials. It occurs in solutions of chiral molecules such as sucrose , solids with rotated crystal planes such as quartz, and spin-polarized gases of atoms...

 of about −6°. The rare (+)-α-copaene is also found in small amounts in some plants. It is of economic significance because it is strongly attracting to an agricultural pest, the Mediterranean fruit fly Ceratitis capitata

Ceratitis capitata

Ceratitis capitata, the Mediterranean fruit fly, or medfly for short, is a species of fruit fly capable of causing extensive damage to a wide range of fruit crops...

.