Popillia japonica pheromone

Females of several species use (R)-5-[(lZ)-l-octenyl]oxacyclopentan-2-one, buibuilactone 69 [ 140-144]. The first y-lactone identified from a scarab beetle was (R)-5-[(Z)-l-decenyl]oxacyclopentan-2-one, japonilure 70, the female produced sex pheromone of the Japanese beetle Popillia japonica [145]. Both 69 and 70 are components of specific blends of several species [140-143]. The Japanese beetle is extremely sensitive to the non-natural enantiomer of his pheromone as little as 1% of the (S)-enantiomer inhibits the attractiveness of the pheromone [ 145]. With respect to species discrimination, this is particularly... 

Kim J.-Y. and Leal W. S. (2000) Ultrastructure of pheromone-detecting sensillum placodeum of the Japanse beetle, Popillia japonica Newmann (Coleoptera Scarabaeidae). Arthropod Struct. Dev. 29, 121-128. 

Nikonov A. A. and Leal W. S. (2002) Peripheral coding of sex pheromone and a behavioral antagonist in the Japanese beetle, Popillia japonica. J. Chem. Ecol. 28, 1075-1089. 

The sex pheromone of the scarabaeid beetle Popillia japonica is a chiral lactone (379) with a (Z)-unsaturated side chain 218). Optically active (/ )(—)-glutamic acid 357, which is converted by retention of configuration via three steps into the Wittig synthon 377, serves as the starting material. Reaction of the latter with the ylide 378 yields the lactone 379 with the desired (R)(Z)-configuration 218) (Scheme 67). 

Tumlinson et al. (1977) were the first to demonstrate inhibition of response to a pheromone by its enantiomer. They synthesised stereospecifically the Z- and f-isomers of both enantiomers of (Z)-5-(l-decenyl)dihydro-2(3H)-furanone, the sex pheromone of the Japanese beetle, Popillia japonica. The purely synthetic (R, Z)-5-(l-decenyl)dihydro-2(3H)-furanone (18) was as effective as the natural isolated pheromone, but male response was strongly inhibited by small amounts of the S- and Z-isomer. 

Treatment of the 1,5-diene (Z,Z)-CHD=CHCH2CH2CH=CHD with potassium permanganate results in stereospecific oxidative cycloaddition to give 40% of the tetrahydrofuran (25), which possesses four chiral centres the (E,E)-isomer behaves in an analogous fashion. " 2,2-Dialkoxytetrahydrofurans are formed from epoxides and keten acetals thus epichlorhydrin reacts with MeCH=C(OMe)2 in the presence of zinc chloride to afford compound (26). The chloro-furanone (27) is obtained as a mixture of cis- and trans-isomers from styrene and trimethylsilyl dichloroacetate in the presence of bis(triphenylphos-phine)ruthenium(ii) chloride. Total syntheses of both enantiomers of the pheromone (28) of the Japanese beetle [Popillia japonica) and of chalcogran (29), the principal pheromone of Pityogenes chalcographus (L.), have been described. 

The Japanese beetle (Popillia japonica) sex pheromone (144) is a lactone with an unsaturated side chain (Scheme 27). Optically active (7 )-(-)-glutamic acid (140 a) served as the starting material in the synthesis by Tumlinson et al 73) shown in Scheme 27. After ring closure with retention of configuration and formation of the aldehyde, inverse addition of the Wittig reagent afforded the desired R,Z configuration. 

The sex attractant of the female Japanese beetle, Popillia japonica, which attracts males, is (Z)-5-(l-decenyl)dihydro-2(3//)-furanone (73). The pure synthetic R,Z-isomer (144, Scheme 27) was competitive with females, and male response was strongly inhibited by small amounts of the 5,Z-isomer. The enantiomeric composition of the natural product has not been determined. The female also produces minor amounts of both the -isomer and the saturated analog but the roles of these compounds has not been established. Females of the California red scale, Aonidiella aurantii, emit a pheromone that attracts males (331). Two compounds have recently been identified and synthesized 3-methyl-6-isopropenyl-9-decen-l-yl acetate (332 a) and (Z)-3-methyl-6-isopropenyl-3,9-decadien-1-yl acetate (333, Scheme 50) (75). The four enantiomers of the latter compound were synthesized and only the R,Z-isomer proved to be attractive to male red scale. 

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