Pinene
Pinene (CH) is a bicyclic monoterpene chemical compound. There are two structural isomers of pinene found in nature: α-pinene and β-pinene. As the name suggests, both forms are important constituents of pine resin; they are also found in the resins of many other conifers, as well as in non-coniferous plants such as camphorweed ("Heterotheca") and big sagebrush ("Artemisia tridentata"). Both isomers are used by many insects in their chemical communication system. The two isomers of pinene constitute the major component of turpentine. Biosynthesis. α-Pinene and β-pinene are both produced from geranyl pyrophosphate, via cyclisation  of linaloyl pyrophosphate followed by loss of a proton from the carbocation equivalent. Researchers at the Georgia Institute of Technology and the Joint BioEnergy Institute have been able to synthetically produce pinene with a bacterium. Plants. Alpha-pinene is the most widely encountered terpenoid in nature and is highly repellent to insects. Alpha-pinene appears in conifers and numerous other plants. Pinene is a major component of the essential oils of "Sideritis" spp. (ironwort) and "Salvia" spp. (sage). "Cannabis" also contains alpha-pinene and beta-pinene. Resin from "Pistacia terebinthus" (commonly known as terebinth or turpentine tree) is rich in  pinene. Pine nuts produced by pine trees contain pinene. Makrut lime fruit peel contains an essential oil comparable to lime fruit peel oil; its main components are limonene and β-pinene. The racemic mixture of the two forms of pinene is found in some oils like eucalyptus oil. Usage. In chemical industry, selective oxidation of pinene with some catalysts gives many compounds for perfumery, such as artificial odorants. An important oxidation product is verbenone, along with pinene oxide, verbenol, and verbenyl hydroperoxide.