Pheromone Monarch butterfly

This sequential substitution of the chloro and acetoxy groups makes the chloroacetates useful as building blocks. An example of the use of the chloroacetate 34 from isoprene for the synthesis of the Monarch butterfly pheromone is given in Scheme 737. Two different nucleophiles, sodium dimethyl malonate and sodium methyl acetoacetate, were employed in Pd(0)-catalyzed allylic substitutions. The transformation of 34 to 36 was also made... 

Monarch butterfly pheromone 366, 367 monocarbonylation of 1,4-enyne system 474... 

By using the chloroacetate generated from isoprene, two enolate nucleophiles were selectively coupled to the 1 - and 4-positions via allylic substitution reaction and the product was subsequently transformed to the Monarch butterfly pheromone [Eq.(46)] [85]. 

Allylic and dienyl sulfones have been prepared by conjugate addition to 1,3-dienes ". Phenylsulfonyhnercuration of conjugated dienes gives mercury adducts which can be treated with base to afford phenylsulfonyldienes. 2-(Phenylsulfonyl)-l,3-dienes can be stereo- and regioselectively functionalized via Michael addition of nucleophiles to give allylic sulfones. A key intermediate in the synthesis of a Monarch butterfly pheromone 4 was prepared by BackvaU and Juntunen by alkylation and subsequent palladium-catalyzed substitution of the allylic sulfone formed by Michael addition of dimethyl malonate to 2-(phenylsulfonyl)-l,3-butadiene (equation 10). 

Further transformed to Monarch butterfly pheromone. h Further converted to ( ,/ )-3,7-dimethyl-2.6-decadicne-l,10-diol. c Further convened to ( + )-mayolide A. MPM = 4-methoxyphenvlmethyl. 

J. Tsuji et al. - Total Synthesis of Monarch Butterfly Pheromone,... 

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... 

The fragmentation is stereospecifically anti as shown by complementary geometry obtained in the cleavage of the epimeric pair of epoxycyclobutanones 91 and 92 (Eq. 110). The fragmentation product 93 of cyclobutanone 91 is transformable into the dimethyl ester of the pheromone of the Monarch butterfly. Considering the availability of the starting epoxy ketones from enones, the oxasecoalkylation serves to reorient the oxidation pattern with chain extension as summarized in Eq. 111. 

One species, the monarch butterfly (Danaus plexippus), anomalous by virtue of its migratory habits, is exceptional also in that it visits PA-containing plants and sequesters PAs, but fails to produce a pheromonal pyrrolizidine (Meinwald et al., 1968 Pliske, 1975a Edgar et al., 1971, 1976a). Such an exception does not obscure the central fact that danaines, as a group, show male sequestration... 

Meinwald J., Chalmers A. M., PliskeT. E. and Eisner T. (1968) Pheromones. III. Identification of trans, fra j -10-hydroxy-3,7-dimethyl-2,6-decadienoic acid as a major component in hairpencil secretion of the male monarch butterfly. Tetrahedron Letters 1968, 4893 1896. 

Structural investigations on the sex pheromones of male butterflies have yielded several unique insect exocrine products. The major components in the hair pencils of the danaid Lycorea ceres ceres are cetyl acetate, (Z)-vaccenyl acetate, and 2,3-dihydro-7-methyl pyrrolizin-l-one (XXIV) (103) The dihydropyrrol izi none, as well as ( , )-3,7-dimethyldeca-2,6-dien-l,10-diol, have been identified from the hair pencils of the queen butterfly, Danaus gilippus (104), and the former compound possesses pheromonal activity when evaluated electrophysiologically (105) and behaviorally (106). The hair pencils of the monarch butterfly, Danaus plexippus, have yielded ( ,E)-10-hydroxy-3,7-dimethyl-2,6-deca dienoic acid (107) and (E,15)-3,7-dimethyl-2,6-decadien-l,10-dioic acid (108). On the other hand, the Old World monarch, Danaus chrysippus, contains (E)-3,7-dimethyloct-2-en-l,8-diol as well as the pyrrolizinone (XXIV) (109). Recently,... 

Monarch butterflies t.g., Danaus plexipus) combine two sets of natural compounds. Larvae feed on plants rich in cardiac glycosides and use them as chemical defense compounds. Adult butterflies visit plants with PAs, where they collect PAs that are converted to pheromones or transferred to their eggs 4,17,31,33,361,515). A similar PA utilization scheme was observed with larvae of the moth Utetheisa ornatrix 367,516), where the compounds were shown to be deterrent for spiders and birds 225, 525). The chrysomelid beetle Oreina feeds on PA-containing plants, such as Adenostyles, and stores the dieUuy PAs in the defense fluid 463,524). 

The Monarch butterfly Danaus plexippus) was found to sequester and store pyrrolizidine alkaloids when fed on homogenized leaves of Senecio vulgaris. It is thought that the presence of these alkaloids in the butterfly may contribute towards its defence mechanism, by making it unpalatable to potential predators. Unlike many other danaids, the Monarch is not dependent on pyrrolizidine alkaloids as precursors of its sex pheromones. 

The hair pencil (an extrusable brush-like structure that serves for pheromone dissemination during courtship) secretion (69) of the Monarch butterfly (Danaus plexippus) consists of sesquiterpenes (Herout, 1970) (Fig. 21.17). The sexual pheromones (69 and 70) of this insect also appear to be terpenoid in origin. 

Pheromonal Secretion of Monardi and Queen Butterfly.—New synthetic routes have been outlined to the degraded terpenoid compounds (198a) and (198b) isolated from the pheromonal secretion of the Monarch butterfly Danausplexippus) and of the related diol (198c) from the male Queen butterfly Danaus gilippus bermice)P ... 

A synthesis of a Queen substance [35] and of the pheromone of Monarch butterfly [36] are additional examples of applications of this particularly useful process. 

Male Monarch butterflies use the pheromones produced by a gland on their wings to make themselves attractive to females. 

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