Chrysanthemic acid | |
---|---|
2,2-Dimethyl-3-(2-methylprop-1-enyl)cyclopropane-1-carboxylic acid
|
|
Identifiers | |
CAS number | 4638-92-0 (1R,3R) or (+)-trans |
PubChem | 16747 (1R,3R) or (+)-trans, 33607 (1S,3S) or (-)-trans, 33606 (1R,3S) or (+)-cis, 20755 (1S,3R) or (-)-cis |
ChemSpider | 15876 (+)-trans, 19543 (-)-cis |
Jmol-3D images | Image 1 |
|
|
|
|
Properties | |
Molecular formula | C10H16O2 |
Molar mass | 168.23 g mol−1 |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
Infobox references |
Chrysanthemic acid is a common chemical intermediate in the production of pyrethroid insecticides. One of the four stereoisomers, (1R,3R)- or (+)-trans-chrysanthemic acid (pictured), is the acid moiety of pyrethrin I, which occurs naturally in the seed cases of Chrysanthemum cinerariaefolium. Many synthetic pyrethroids, for example the allethrins, are esters of all four stereoisomers.
Synthesis
Chrysanthemic acid is produced industrially in a cyclopropanation reaction of a diene as a mixture of cis- and trans isomers, followed by hydrolysis of the ester[1]:
Many pyrethroids are accessible by re-esterification of crysanthemic acid ethylester.
References
- ^ A synthesis of chrysanthemic ester: An undergraduate experiment. Kelly, Lawrence F. J. Chem. Educ. 1987, 64, 1061.