Pheromone stability

Butler, C.G., Callow, R.K. and Chapman, J.R. (1964). 9-Hydroxydec-tra j-2-enoic acid, a pheromone stabilizing honey bee swarms. Nature 201,733. 

Minor constit. of royal jelly. A pheromone stabilizing honey-bee swarms. Oil. 

For trisubstituted olefins, the nucleophile attacks predominantly at the less substituted end of the allyl moiety, e.g. to afford a 78 22 mixture of 13 and 14 (equation 7). Both the oxidative addition of palladium(O) and the subsequent nucleophilic attack occur with inversion of configuration to give the product of net retention7. The synthesis of the sex pheromone 15 of the Monarch butterfly has been accomplished by using bis[bis(l,2-diphenylphosphinoethane)]palladium as a catalyst as outlined in equation 87. A substitution of an allyl sulfone 16 by a stabilized carbon nucleophile, such as an alkynyl or vinyl system, proceeds regioselectively in the presence of a Lewis acid (equation 9)8. The... 

Watts, R.A., Palmer, C.A., Feldhoff, R.C., Feldhoff, P.W., Houck, L.D., Jones, A.G., Pfren-der, M.E., Rollmann, S.M. and Arnold, S.J. (2004) Stabilizing selection on behavior and morphology masks positive selection on the signal in a salamander pheromone signaling complex. Mol. Biol. Evol. 21, 1032-41. 

Pheromones.—A careful examination of the factors which affect the ratio of the cis-cis- and mww-c/.y-alkenes formed from the reaction of thealdehyde (69) with a non-stabilized ylide has been described.70 Methods were specifically developed to give the... 

In contrast, the corresponding reactions of RCu/BFa reagents (R = phenyl or alkenyl) with allylic acetals obviously proceed in an anti 5n2 fashion, as shown in (67b). The unsaturated acetals (68), prepared from (R )-butane-1,2-diol, are opened by the PBu3-stabilized reagents to give, after hydrolysis, the (3-substituted aldehydes (69) with high ee (Scheme 27).68,69 The method has been applied to the preparation of a key intermediate (85% ee) for the synthesis of the California red scale pheromone.69... 

Figure 6.16 Model illustrating interspecific regulatory differences in an early-stage reaction in isoprenoid pheromone biosynthesis between male Ips paraconfusus Lanier and Ips pini (Say). Feeding on host phloem results in synthesis of the full amount of the major pheromone component and full activity of HMG-R for both species. The impact of feeding on HMG-R transcript levels is yet to be determined. Topical treatment of male I. pini with JH III mimics feeding nearly completely in terms of pheromone mass and HMG-R activity. Topical treatment of male I. paraconfusus with JH III does not mimic feeding in terms of pheromone mass or HMG-R activity. Topical treatment of both species with JH III results in significantly enhanced levels of HMG-R transcript. One hypothetical explanation for the interspecific difference is that a second hormone (SH) or factor may be associated with the synthesis, stability, and/or activity of HMG-R in I. paraconfusus.

One of the reported syntheses of ( )-9-oxodec-2-enoic acid 392, the queen substance of the honey bee Apis mellifera, uses two ylide reactions 222). Starting from pimelic acid 385 the resonance-stabilized ylide 386 is prepared by alkylation of methylene-triphenylphosphorane 209 and the former hydrolyzed to 7-oxooctanoic acid 387. Reduction of the corresponding thiol ester 389 and olefination of the resulting aldehyde 390 with phosphorane 67 gives the ( )-2-unsaturated ester 391. The latter was hydrolyzed to pheromone 392 222) (Scheme 69). 

The female silkworm moth attracts mates by producing a pheromone known as stabilized and unstabilized ylids, respectively, to control the stereochemistry of bombykol. Bombykol is an E.Zdiene, and in this synthesis (dating from 1977) the product, two successive Wittig reactions exploit the stereoselectivity obtained with... 

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. 

The above studies were carried out using the simple, exposed thin-film system. Microencapsulated formulations of Z9-14 Ac and 14 Ac were made up containing the N,N -dimethyl UOP 688 and/or Waxoline Black, and tested in exposure experiments in Egypt. The N,N -dimethyl UOP 688 alone stabilised the pheromone but seemed to have little effect on the degradation of the capsule walls (Fig. 3), while the Waxoline Black alone had a greater effect on the stability of the capsules than on that of the pheromone (Fig. 4). Combination of the two had a synergistic effect on the stabilities of the microcapsule wall and the pheromone (Fig. 5). 

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