Laballenic acid
Chemical compound
From Wikipedia, the free encyclopedia
Laballenic acid is a linear fatty acid composed of 18 carbon atoms, with two consecutive double bonds (allene) in position 5=6=7. It has the structural formula CH3(CH2)10−CH=C=CH−(CH2)3COOH.
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| Names | |
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| Other names
5,6-octadecadienoic acid | |
| Identifiers | |
3D model (JSmol) |
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| 1911935 | |
| ChEBI | |
| ChemSpider | |
PubChem CID |
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| Properties | |
| C18H32O2 | |
| Molar mass | 280.452 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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The acid is one of the rare allenic fatty acids found in nature.[1]
Discovery
The acid was initially isolated in 1964 from the seed oil of Leonotis nepetifolia, a plant of the family Lamiaceae by M.O. Bagby, C.R. Smith Jr., and I.A. Wolff, and identified by the same authors a year later.[2][3]
Laballenic acid has also been found in Phlomoides tuberosa.
Synthesis
Several methods of synthesis have been published.[4] An efficient and enantioselective synthesis dates back to the year 2022. A further enantioselective synthesis is based on copper(II) bromide catalysis and the use of diphenylprolinol as a chiral auxiliary.[5]
It has also been reported that lamenallenic acid is probably biosynthesized from laballenic acid.[6]
Physical properties
Laballenic acid has axial chirality and is therefore optically active.[7][8] The absolute configuration of laballenic acid was determined by stereoselective synthesis.[9]
There exist two configurations: the (R)-form and the (S)-form of laballenic acid.[10] The naturally occurring acid has the R-configuration: it is an isomer of linoleic acid related with the similar phlomic acid.[11]