Fruit fly, pheromone

Birch reduction-methylation of the 2,3-dialkyl substituted benzamide 85 (Scheme 19) provided the cyclohexa-1,4-diene 86 with diastereoselectivity comparable to that observed with the 2-alkylbenzamides illustrated in Scheme 4. Cyclohexadiene 86 was converted to iodolactone 87 and reduction of 87 with BusSnH occurred with exclusive equatorial delivery of hydrogen to give the axial methoxyethyl derivative 88. Lactone 88 was converted to the Caribbean fruit fly pheromone (+)-epia-nastrephin 90 (> 98% ee) in 9.5% overall yield from the chiral benzamide 85. °... 

Synthesis of Haptens and the development of an enzyme-linked immunoassay (ELISA) for the olive fruit fly pheromone, Bactrocera oleae has been reported. 

The fact that the substituents on the side chains can control the conformation of the spiroketal centre means that it is not necessary to worry about that centre in a synthesis, provided you are trying to make the spiroketal that has the double anomeric stabilization (both oxygens axial) and that has any substituents equatorial on the rings. A recent (1997) synthesis of a single enantiomer of some fruit-fly pheromones from an aspartic acid-derived bromodiol is shown overleaf. It involves three different-sized oxygen heterocycles. 

Pheromone (sex attractant). Ether extract of the stem, produced equivocal effect on Aspiculuris tetraptera, female and male Dacus dorsalis, male Mediterranean fruit flies, and male and female melon flies " k Pheromone (signaling). Ether extract of the stem, produced equivocal effect on Aspiculuris tetraptera, female and male Dacus dorsalis, male Mediterranean fruit flies, and male and female melon flies " k Phospholipidemic effect. Oil, administered to phospholipids transfer protein knockout (PLTPO)-deficient mice, produced an increase of phospholipids and free cholesterol in the VLDL-LDL region of PLTPO mice. Accumulation of phospholipids and free cholesterol was dramatically increased in PLTPO/HLO mice compared to PLTPO mice. Turnover studies indicated that coconut oil was associated with delayed catabolism of phospholipids and phospho-lipids/free cholesterol-rich particles. Incubation of these particles with hepatocytes of coconut-fed mice produced a reduced removal of phospholipids and free cholesterol by SRBI, even though SRBI protein expression levels were unchanged . 

Fletcher B. S. (1969) The structure and function of the sex pheromone glands of the male Queensland fruit fly, Dacus tryoni. J. Insect Physiol. 15, 1309-1322. 

Oguma Y., Nemoto T. and Kuwahara Y. (1992b) A sex pheromone study of a fruit fly Drosophila virilis Sturtevant (Diptera Drosophilidae) additive effect on cuticular alkadienes to major sex pheromone. Appl. Entomol. Zool. 27, 499-505. 

In particular, the importance of chirality in diverse pheromone systems has been reviewed recently (Mori, 1998). For example, olive fruit flies (Bactrocera oleae) emit racemic 2 the males detect the R enantiomer, while females detect the S (Haniotakis et al., 1986). The sex pheromone of the Osaka beetle (Anomala osakana) is 4a, while the closely related Japanese beetle (Popilia japonica) uses 4b (Table 16.1). Interestingly, 4a is a powerful behavioral antagonist in P. japonica (Tumlinson et al., 1977). The hemlock looper, Lambdina fiscellaria, responds only to (5R, 1 S)-5,I I -dimethylheptadecane. The enantiomer or the R/R or S/S diastereomers do not elicit electrophysiological or behavioral responses (Li et al., 1993). Table 16.1 gives an overview of those species where proteins from the pheromone olfactory system have been identified. 

Ebbs, M. L. and Amrein, H. (2007). Taste and pheromone perception in the fruit fly, Drosophila melanogaster. Pflugers Arch - Eur. J. Physiol., 454, 735-747. 

The simple compound 79 is an aggregation pheromone of the fruit fly Drosophila mulleri. Hoppe proposed to synthesise it by asymmetric deprotonation and retentive methylation of a carbamate derivative of n-dodecanol.8 Given that the carbamate group (required for directed oc-lithiation) must, at the end of the synthesis, be removed from the molecule, the best choice is the tetramethyloxazolidine-derived 81, readily formed by acylation with the carbamoyl chloride 80. Lithiation of 81 with excess s-BuLi-(-)-sparteine gives, by asymmetric deprotonation, a configurationally stable complex of organolithium 82 with (-)-sparteine. 

Now that you know about the anomeric effect, you should add it to your mental array of ways of explaining unexpected results. Here is an example. Many fruit flies have pheromones based around a spiroketal structure, which we could represent without stereochemistry as shown below. You can imagine the spiroketal (that is, an acetal of a ketone made of two rings joined at a single atom) being made from a dihydroxyketone—and, indeed, this is very often how they are made synthetically. But this is a bad representation because these compounds do have stereochemistry, and the stereochemistry is very interesting. 

Two important spiroketals, such as l,7-dioxaspiro[5.6]undecane (29a), the major component of the olive fruit fly (Dacus oleae) sex pheromone (Baker et ah, 1980 Fanelli et ah, 1983), and ( )-2-methyl-l,7-dioxaspiro[5.6]dodecane (29b), a component of pheromone of Andrena haemorrhoa (Bergstroem et al., 1981 Katsurada and Mori, 1984), have been prepared in a cascade process from polyfunctionalized nitroalkanes (26) (Ballini and Petrini, 1992). 

This is a review of synthetic efforts made at these laboratories in recent years. Stereoisomers of sex pheromones of various insect species were synthesized in order to facilitate identification and permit more thorough evaluation of their potential in insect control programs. Syntheses are described for pheromones of the stable fly, tsetse fly, southern and western corn rootworms, and the Mediterranean fruit fly attractant, trimed-lure. In each instance centers of asymmetry were generated that made use of diastereomer formation using readily available (R)- and (S)-a-methyl-benzylamine. Resolutions were achieved either by preparative HPLC, or fractional crystallization of amides. The latter technique was rendered synthetically useful for the preparation of configurationally pure acids by virtue of transformations wrought upon the amides that made them subject to cleavage under very mild conditions. 

Since, the original presentation of this paper, the pheromone of the Mediterranean fruit fly has been identified (23). The compounds, 3,4-dihydro-2H-pyrrole, ethyl-E-3-octenoate, E,E,-0(-farnesene, and geranyl acetate, bear no obvious resemblance to the active components of trimedlure. The origin of the biological activity of the synthetic, therefore, remains enigmatic. 

The intermediate 122 is a stable compound and can be made by any chemistry that gives simple alcohols. Acylation of 128 with a lactone gives the hydroxy ketone 132 and reduction gives the anti-diol 133 in excellent yield. Elimination gives pure -134, a pheromone of the Mediterranean fruit fly. 

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