Chiral-phase capillary gas chromatography and mosquito repellent activity of some oxazolidine derivatives of (+)- and (-)-citronellol.
Fourteen stereoisomeric mixtures of six oxazolidine heterocycles and one amino alcohol were obtained from commercial samples of (+)-, (-), or (+/-)-citronellol and evaluated in a cloth test system as mosquito repellents. A technical sample of 3-acetyl-2-(2',6'-dimethyl-5'-heptenyl)oxazolidine, evaluated initially as a mixture of two pairs of enantiomers, was an effective repellent against two of the three species of mosquitoes. To study repellency-stereochemistry relationships, 1 was isolated as fractions G-1, G-2, I-1, and I-2, corresponding to representative samples of the four possible stereoisomers. The enantiomeric composition of 1, but not of the other derivatives, could be determined by chiral-phase capillary gas chromatography with Chirasil-Val. Two chiral phases showed that experimental samples of 1, and hence the commercial samples of 2, were composed of not more than 90% of one enantiomer. Differences in repellency of isomerically enriched samples were generally small. Fraction G, a mixture of diastereoisomers readily prepared from (+)-2, was considerably more effective than standard insect repellents in bioassays with three mosquito species.
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D000080462:Acyclic Monoterpenes; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D055598:Chemical Phenomena; D002621:Chemistry; D002849:Chromatography, Gas; D009033:Culicidae; D007302:Insect Repellents / Q000032:analysis*; D039821:Monoterpenes; D013237:Stereoisomerism; D013729:Terpenes / Q000032:analysis* / Q000494:pharmacology
D000080462:Acyclic Monoterpenes; D007302:Insect Repellents; D039821:Monoterpenes; D013729:Terpenes; C007078:citronellol