| |||
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 | |||
3D model (
JSmol)
|
| ||
ChEBI |
| ||
ChemSpider | |||
ECHA InfoCard | 100.014.121 | ||
EC Number |
| ||
KEGG | |||
PubChem
CID
|
|||
UNII |
| ||
CompTox Dashboard (
EPA)
|
| ||
| |||
| |||
Properties [1] | |||
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 | ||
Insoluble (α and β) | |||
Hazards | |||
GHS labelling: | |||
Danger | |||
H226, H304 | |||
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 [77 °F], 100 kPa).
|
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. [2] It is also a constituent of the essential oil of Eucalyptus dives. [3] 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. [4]
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. [5]
{{
cite book}}
: CS1 maint: location missing publisher (
link)
| |||
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 | |||
3D model (
JSmol)
|
| ||
ChEBI |
| ||
ChemSpider | |||
ECHA InfoCard | 100.014.121 | ||
EC Number |
| ||
KEGG | |||
PubChem
CID
|
|||
UNII |
| ||
CompTox Dashboard (
EPA)
|
| ||
| |||
| |||
Properties [1] | |||
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 | ||
Insoluble (α and β) | |||
Hazards | |||
GHS labelling: | |||
Danger | |||
H226, H304 | |||
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 [77 °F], 100 kPa).
|
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. [2] It is also a constituent of the essential oil of Eucalyptus dives. [3] 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. [4]
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. [5]
{{
cite book}}
: CS1 maint: location missing publisher (
link)