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.
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.It is colorless to light yellow oily liquid with peppermint aroma. Right-handed body exists in cinnamon oil, ginger oil, elemi oil, cumin oil etc. Left-handed body exists in eucalyptus oil, star anise oil, gump couch oil, laurel oil, pepper oil, etc.
α-Phellandrene was named after Eucalyptus phellandra, now called Eucalyptus radiata, from which it can be isolated. It is also a constituent of the essential oil of Eucalyptus dives.