Longifolene
Chemical compound
From Wikipedia, the free encyclopedia
Longifolene is a common sesquiterpene. It is an oily liquid hydrocarbon found primarily in the high-boiling fraction of certain pine resins. The name is derived from that of a pine species from which the compound was isolated.[1] It is a tricyclic chiral molecule. The enantiomer commonly found in pines and other higher plants exhibits a positive optical rotation of +42.73°. The other enantiomer (optical rotation −42.73°) is found in small amounts in certain fungi and liverworts.
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| Names | |
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| IUPAC name
(1R,2S,7S,9S)- 3,3,7-trimethyl- 8-methylenetricyclo- [5.4.0.02,9]undecane | |
| Identifiers | |
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3D model (JSmol) |
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| 5731712 2044263 4663756 | |
| ChEBI |
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| ChemSpider | |
| ECHA InfoCard | 100.006.812 |
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PubChem CID |
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| UNII |
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CompTox Dashboard (EPA) |
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| Properties | |
| C15H24 | |
| Molar mass | 204.36 g/mol |
| Density | 0.928 g/cm3 |
| Boiling point | 254 °C (489 °F; 527 K) (706 mm Hg) |
| Hazards | |
| GHS labelling: | |
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| Danger | |
| H304, H317, H410 | |
| P261, P272, P273, P280, P301+P310, P302+P352, P321, P331, P333+P313, P363, P391, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Occurrence
Terpentine obtained from Pinus longifolia (obsolete name for Pinus roxburghii Sarg.) contains as much as 20% of longifolene.[2]
Longifolene is also one of two most abundant aroma constituents of lapsang souchong tea, because the tea is smoked over pinewood fires.[3]
Biosynthesis
The biosynthesis of longifolene begins with farnesyl diphosphate (1) (also called farnesyl pyrophosphate) by means of a cationic polycyclization cascade. Loss of the pyrophosphate group and cyclization by the distal alkene gives intermediate 3, which by means of a 1,3-hydride shift gives intermediate 4. After two additional cyclizations, intermediate 6 produces longifolene by a 1,2-alkyl migration.
