Phellandrene

Phellandrene is the name for a pair of organic compounds that have a similar molecular structure and similar chemical properties. α-Phellandrene and β-phellandrene are cyclic monoterpenes and are double bond isomers. In α-phellandrene both double bonds are endocyclic and in β-phellandrene one of them is exocyclic. Both are insoluble in water, but miscible with ether.

α-Phellandrene is a constituent of the essential oils of Eucalyptus dives and of Eucalyptus phellandra (hence the name). β-Phellandrene has been isolated from the oil of water fennel and Canada balsam oil.

The phellandrenes are used in fragrances because of their pleasing aromas. The odor of β-phellandrene has been described as peppery-minty and slightly citrusy.