Phellandrene

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α-Phellandreneα-Phellandrene

β-Phellandreneβ-Phellandrene

Names

IUPAC names (α): 2-Methyl-5-(propan-2-yl)cyclohexa-1,3-diene
(β): 3-Methylidene-6-(propan-2-yl)cyclohex-1-ene

Identifiers

CAS Number

(α): 99-83-2 Y
(β): 555-10-2 Y
(−)-(α): 4221-98-1 Y
(+)-(α): 2243-33-6 Y

3D model (JSmol)

ChEBI

(β): CHEBI:48741
(−)-(α): CHEBI:301
(+)-(α): CHEBI:367
(−)-(β): CHEBI:129
(+)-(β): CHEBI:53

ChemSpider

(α): 7180 N
(β): 10669 N

ECHA InfoCard

100.014.121

EC Number

(α): 202-792-5
(β): 209-081-9
(−)-(α): 224-167-6

KEGG

(−)-(α): C09875
(+)-(α): C11391
(−)-(β): C11392
(+)-(β): C09877

PubChem CID

(α): 7460
(β): 11142
(−)-(α): 442482
(+)-(α): 443160
(−)-(β): 443161

UNII

(α): 49JV13XE39 Y
(β): 2KK225M001 Y
(−)-(α): 56UV8X65K0 Y
(+)-(α): E45FS72C5K Y

CompTox Dashboard (EPA)

(α): DTXSID8051673

InChI

(α): InChI=1S/C10H16/c1-8(2)10-6-4-9(3)5-7-10/h4-6,8,10H,7H2,1-3H3Key: OGLDWXZKYODSOB-UHFFFAOYSA-N
(β): InChI=1S/C10H16/c1-8(2)10-6-4-9(3)5-7-10/h4,6,8,10H,3,5,7H2,1-2H3Key: LFJQCDVYDGGFCH-UHFFFAOYSA-N
(−)-(α): InChI=1S/C10H16/c1-8(2)10-6-4-9(3)5-7-10/h4-6,8,10H,7H2,1-3H3/t10-/m1/s1Key: OGLDWXZKYODSOB-SNVBAGLBSA-N
(+)-(α): InChI=1S/C10H16/c1-8(2)10-6-4-9(3)5-7-10/h4-6,8,10H,7H2,1-3H3/t10-/m0/s1Key: OGLDWXZKYODSOB-JTQLQIEISA-N

SMILES

(α): CC1=CCC(C=C1)C(C)C
(β): CC(C)C1CCC(=C)C=C1
(−)-(α): CC1=CC(C=C1)C(C)C
(+)-(α): CC1=CC(C=C1)C(C)C

Properties

Chemical formula

C10H16

Molar mass

136.24 g/mol

Appearance

Colorless oil (α and β)

Density

α: 0.846 g/cm3
β: 0.85 g/cm3

Boiling point

α: 171-172 °C
β: 171-172 °C

Solubility in water

Insoluble (α and β)

Hazards

Danger

H226, H304

Precautionary statements

P210, P233, P240, P241, P242, P243, P280, P301+P310, P303+P361+P353, P331, P370+P378, P403+P235, P405, P501

Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa).

N verify (what is

N ?) Infobox references

Phellandrenes are 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 diethyl ether.

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. 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.

The α-phellandrene isomer can form hazardous and explosive peroxides on contact with air at elevated temperatures.

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 allylic carbocation. Finally, an elimination reaction occurs at one of two positions, yielding either α-phellandrene or β-phellandrene.

References

^ The Merck Index, 12th Edition, 7340, 7341
^ Jacobs, S.W.L., Pickard, J., Plants of New South Wales, 1981, ISBN 0-7240-1978-2.
^ Boland, D. J., Brophy, J. J., and A. P. N. House, Eucalyptus Leaf Oils, 1991, ISBN 0-909605-69-6.
^ Urben, Peter (2007). Bretherick's Handobook of Reactive Chemical Hazards. Vol. 1 (7 ed.). Butterworth-Heinemann. p. 1154.
^ Dewick, Paul M. (9 March 2009). Medicinal natural products : a biosynthetic approach (3rd ed.). Chichester, West Sussex, United Kingdom. ISBN 9780470741689. OCLC 259265604.{{cite book}}: CS1 maint: location missing publisher (link)