Product Code Database
Phellandrenes are with the formula . They have a similar molecular structure and similar chemical properties. α-Phellandrene and β-phellandrene are cyclic terpene and are double-bond . In α-phellandrene, both double bonds are endocyclic, and in β-phellandrene, one of them is exocyclic. Both are insoluble in water, but miscibility with organic solvents.
β-pinene is a source of β-phellandrene.
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.
Like other cyclohexadienes, α-phellandrene reacts with ruthenium trichloride to give (cymene)ruthenium chloride dimer.
Reactions and uses
α-Phellandrene undergoes hydrochlorination to give phellandrene hydrochloride (a cyclohexenyl chloride). Base hydrolysis of this hydrochloride gives piperitol.
Biosynthesis
The biosynthesis of phellandrene begins with dimethylallyl pyrophosphate and isopentenyl pyrophosphate condensing in an SN1 reaction to form geranyl pyrophosphate. The resultant monoterpene undergoes cyclization to form a menthyl cationic species. A hydride shift then forms an carbocation. Finally, an elimination reaction occurs at one of two positions, yielding either α-phellandrene or β-phellandrene.
Safety
The α-phellandrene isomer can form hazardous and explosive peroxides on contact with air at elevated temperatures.
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