/pdf/are-alkyne-reductions-chemo-regio-and-stereoselective-enough-2k025fyx4w.pdf

Are alkyne reductions chemo-, regio-, and stereoselective enough to provide pure (Z)-olefins in polyfunctionalized bioactive molecules?

Although several sex pheromones of the family Geometridae have been characterized, investigations on Japanese species are limited. In order to obtain more information, screening using known sex pheromones and their analogs was carried out. The (Z,Z,Z)-3,6,9-triunsaturated and (Z,Z)-6,9-diunsaturated hydrocarbons with straight C19-C21 chains were synthesized by the Grignard coupling reaction as a key step starting from linolenic and linoleic acids, respectively. Oxidation of the homoconjugated trienes withm-chloroperoxybenzoic acid yielded a 1∶1∶1 mixture of three monoepoxy derivatives that could be separated by silica gel chromatography. The chemical structure of each positional isomer was confirmed using two-dimensional NMR techniques and MS measurements, which enabled characteristic fragment ions from the isomers to be identified. Field tests using lures incorporating only one of the above six hydrocarbons or nine epoxides were carried out in a forest in Tokyo. Consequently, attraction of male moths of 14 geometrid species in addition to four species in another family, the Noctuidae, was observed. It was concluded that hydrocarbons with a homoconjugated polyene system and the monoepoxy derivatives are important components of sex pheromones produced by Japanese lepidopterous insects, particularly the geometrid moths.

Hydrocarbons with a homoconjugated polyene system and their monoepoxy derivatives: Sex attractants of geometrid and noctuid moths distributed in Japan.

Enantiomer separation of (6Z,9Z)-cis-3,4-epoxynonadecadiene and (3Z,9Z)-cis-6,7-epoxynonadecadiene could be achieved using chiral high-resolution gas chromatography and a cyclodextrin-bond column. (3Z,9Z)-(6R,7S)-Epoxynonadecadiene was identified from ovipositor extracts ofColotois pen-Naria, while inErannis defoliaria the 6S,7R-enantiomer was found. In field trapping tests pure synthetic enantiomers caught only conspecific males of these species. (3Z,6Z,9Z)-Nonadecatriene was found in both species, while the presence of (3Z,6Z,9Z)-heneicosatriene was indicated inC. Pennaria only. A 10∶10∶3 blend of (3Z,9Z)-(6R,7S)-epoxynonadecadiene, (3Z,6Z,9Z)-heneicosatriene, and (3Z,6Z,9Z)-nonadecatriene was found to be optimal for catchingC. Pennaria, whileE. Defoliaria males were optimally caught by a 1∶1 mixture of (3Z,9Z)-(6S,7R)-epoxynonadecadiene and (3Z,6Z,9Z)-nona-decatriene. (6Z,9Z)-(3S,4R)-Epoxynonadecadiene was identified from ovipositor extracts ofAgriopis (Erannis) aurantiaria. In field tests the pure enantiomer proved to be a highly specific sex attractant for both the late autumn/early winter flyingA. Aurantiaria and the late winter/early spring flyingA. Leucophearia. Males ofAgriopis marginaria, which fly in late winter/early spring, were attracted to (3Z,9Z)-(6S,7R)-epoxynonadecadiene. The addition of (3Z,6Z,9Z)-nonadecatriene to theS,R-enantiomer increased captures. Optimal catches were recorded with a 10∶3 epoxide-hydrocarbon blend. Enantiomer specificity in all species was confirmed in EAG measurements.

Species discrimination in five species of winter-flying geometrids (Lepidoptera) based on chirality of semiochemicals and flight season

The Japanese giant looper, Ascotis selenaria cretacea, is a serious defoliator of tea gardens in Japan. GC-MS analysis of the virgin female extract confirmed the presence of (Z,Z)-6,9-cis-3,4-epoxynonadecadiene. This compound had attracted male moths in a previous random screening test using C17–C23 epoxydienes synthesized in a racemic form. Further GC and HPLC analyses with chiral columns showed that the natural pheromone was composed of 3S,4R and 3R,4S isomers in a ratio of 53:47, although the field evaluation revealed stronger activity of the pure 3R,4S epoxide than of other enantiomeric mixtures. This result indicates that the sexual communication system of this Japanese subspecies differs from that of the species in Israel, which is selectively attracted to an isomer with the opposite configuration. Interestingly, the 3S,4R epoxide attracted another geometric male, Alcis angulifera, in our field tests. (Z,Z,Z)-3,6-9-Nonadecatriene, a parent olefinic compound of the epoxy pheromone, was also identified in the gland extract of A. s. cretacea, but its effect on the attractive activity of the epoxide was not assured in field tests. The amount of the triene increased in the virgin female during photophase and also after decapitation. The epoxy component completely disappeared after decapitation, but could be increased by an injection of subesophageal ganglion extract. The data suggest that the triene is a biosynthetic precursor of the epoxide and that a neuropeptide hormone (PBAN) regulates the epoxydation.

Sex Pheromone of Japanese Giant Looper, Ascotis selenaria cretacea : Identification and Field Tests

Construction of (Z,Z) Skipped 1,4-Dienes. Application to the Synthesis of Polyunsaturated Fatty Acids and Derivatives

Identification and enantioselective synthesis of (Z,Z)-6,9-cis-3S,4R-epoxynonadecadiene, the major sex pheromone component of Boarmia selenaria

(Z,Z)-6,9-cis-(3S,4R)-Epoxynonadecadiene9a and (Z,Z,Z)-3,6,9-nonadecatriene have been identified as sex pheromone components in female ovipositor extracts and effluvia of the geometridBoarmia selenaria. The identification was based on relative retention times on gas chromatographic columns, GC-MS, chemical enantioselective syntheses, EAG, wind-tunnel behavioral experiments, and field tests. A single female ovipositor extract contained an average of 42 ng of (Z,Z)-6,9-cis-3,4-epoxynonadecadiene and 2 ng of (Z,Z,Z)-3,6,9-nonadecatriene.EAG, wind-tunnel behavioral studies, and field tests demonstrated that maleB. selenaria exhibit preferential attraction for the (3S,4R)-enantiomer of (Z,Z)-6,9-cis-3,4-epoxynonadecadiene. Only in effluvia and ovipositor extracts of calling females was (Z,Z)-6,9-cis- 3,4-epoxynonadecadiene detected, whereas relatively high amounts of (Z,Z,Z)-3,6,9-nonadecatriene were found in noncalling females. Wind-tunnel behavioral studies showed that (Z,Z,Z)-3,6,9-nonadecatriene did not elicit any response in the males, and when tested in combination with a mixture of monoepoxynonadecadienes, (Z,Z,Z)-3,6,9-nonadecatriene decreased the observed behavioral responses. A possible precursor role for (Z,Z,Z)-3,6,9-nonadecatriene in the pheromonal system is discussed.

Sex pheromone components of the giant looper,Boarmia selenaria schiff. (Lepidoptera: Geometridae): Identification, synthesis, electrophysiological evaluation, and behavioral activity

Identification and Enantioselective Synthesis of Z,Z-6,9-cis-3S,4R- Epoxynonadecadiene (I), a Sex Pheromone Component of Boarmia selenaria.

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Identification and enantioselective synthesis of (Z,Z)-6,9-cis-3S,4R-epoxynonadecadiene, the major sex pheromone component of Boarmia selenaria

Sex pheromone components of the giant looper,Boarmia selenaria schiff. (Lepidoptera: Geometridae): Identification, synthesis, electrophysiological evaluation, and behavioral activity

Identification and Enantioselective Synthesis of Z,Z-6,9-cis-3S,4R- Epoxynonadecadiene (I), a Sex Pheromone Component of Boarmia selenaria.