Mosquito pheromone

Olefin metathesis can be very useful in the CM mode, as shown in the synthesis of insect phere-mones.46 In the first example for the synthesis of the peach twig borer pheromone 23, an excess of 1-hexene was used to increase the yield of the desired product. However, both of the other products could be recycled (Scheme 28.17). In the second example, CM was used to change the ester groups of meadowfoam oil (24) through cleavage of the alkenes rather than ester bonds. The sequence resulted in the synthesis of the mosquito pheromone (25) (Scheme 28.18). 

Addition of BuiSnLi to cyclohex-2-enone followed by enolate trapping with n-decyl iodide proceeded with high diastereoselectivity to provide the 2,3-rrdiR5-stannyl ketone (16), which could be equilibrated with the cis diastereomer (17) upon treatment with base. LAH reduction, followed by separation of the diasteteomers, afforded samples of the 2-alkyl-3-stannylcyclohexanols as shown in Scheme 17. Iodine(III)-mediated fragmentation was shown to proceed in a stereospecific anti manner, with either of the rrdiRr-2,3-cyclohexanols affording ( )-enal (18), and the cir-2,3-alcohol the (Z)-enal (19 Scheme 17). Enal (18) was then utilized in a stereoselective synthesis of the mosquito pheromone, erythro-6-asx-toxyhexadiecan-S-olide (20 Scheme 18). ... 

Rahman, S.S., B.J. Wakefield, S.M. Roberts, and M.D. Dowle Intramolecular Nucleophilic Addition to Photochemically Generated Ketones as a Versatile Route to Lactones and Lactams Synthesis of a Mosquito Pheromone, Goniothalamin, Argentilactone and the Streptomyces L-factor. Chem. Commun., 303 (1989). 

Scheme 41 summarizes Couladouros s synthesis of the oviposition attractant pheromone of the Southern house mosquito (Culexpipiensfatigans)y (5R,6S)-6-acetoxy-5-hexadecanolide (28) [66]. The key-steps are (i) -selective Schlosser olefination (A B), asymmetric dihydroxylation (B C), and lactonization of carbonate C to the desired 6-lactone with inversion at C-5. 

Synthesis of (—)-(5i , 6S)-6-acetoxyhexadecanolide, a mosquito oviposition pheromone of Culexpipiens fatigans, was also prepared by asymmetric synthesis. 

Based on the previous work of this group on the three-component aza[4+2]/ allylboration strategy to construct polysubstituted piperidines [62], Gao and Hall developed a catalytic enantioselective version [63] of the corresponding oxygeneous process to construct a-hydroxyalkylated pyrans from 3-boronoacrolein [64], This recent variant of a Vaultier-Lallemand one-pot three-component reaction (see Scheme 12.14) was successfully applied to a concise total synthesis of (5R,6S)-6-acetoxy-5-hexadecanolide 128 (Scheme 12.20), the oviposition attractant pheromone of the female Culex mosquito [65] capable of transmitting the West Nile virus. 

R,6R) diastereoisomer (Scheme 7). Again, from 34 the (5R,6R) product 43 was obtained. Products 42 and 43 represent the two enantiomers of the proposed major component of a mosquito oviposi-tion attractant pheromone (18). The enantiomeric forms of 5-hexadecanolide, 44 and 45, the pheromone of Vespa orientalis, were obtained from the enantiomeric aldehydes 34 and 37 (19). All the compounds obtained up to this point have been prepared in both enantiomeric forms, starting from a single chiral material. 

Mosquito (Culex quinquefasciatus C. tarsalis) responses Likely attractant for predators on insect herbivores (OD-R) Ant (Formica lugubris) male pheromone Mosquito (Culex quinquefasciatus,... 

Couladouros, E. A., Mihou, A. P. A general synthetic route towards y- and 5-lactones Total asymmetric synthesis of (-)-muricatacin and the mosquito oviposition pheromone (5R,6S)-6-acetoxy-hexadecanolide. Tetrahedron Lett. 1999, 40,4861-4862. 

R.6S) 6 acetoxyhexadeca n-5-olidc Natural mosquito attractant pheromone Atr Proline catalyzed asymmetric aldol reaction 186 ... 

Alioto TS, Ngai J (2005) The odorant receptor repertoire of teleost fish. BMC Genomics 6 173 Anton S et al (2003) Central projections of olfactory receptor neurons from single antennal and palpal sensilla in mosquitoes. Arthropod Struct Dev 32 319-327 Bartelt RJ et al (1985) cis-Vaccenyl acetate as an aggregation pheromone in Drosophila mela-nogaster. J Chem Ecol 11 1747-1756... 

Ha TS, Smith DP (2006) A pheromone receptor mediates 11-cis-vaccenyl acetate-induced responses in Drosophila. J Neurosci 26 8727-8733 Hallem EA et al (2004a) Olfaction mosquito receptor for human-sweat odorant. Nature 427 212-213... 

An egg parasitoid uses the sex pheromone of the tussock moth to find the eggs, which are deposited shortly after mating.168 An oviposition attractant for the mosquito, Culexpipiens fatigans, is shown (11.38).169... 

The enantiospecific synthesis of ( + )-ef7r/zro-(5 S, 6i )-6-acetoxy-5-hexadecanolide (475), an optically active form of the major component of an oviposition attractant pheromone of the mosquito Culexpipiens fatigans, exploits the 6,8-dioxabicyclo[3.2.1]octane system to provide... 

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