Tea tortrix moth

The smaller tea tortrix moth (Adoxophyes honmai) uses (/ )-124 as a minor component of its pheromone bouquet, and (R)- 2A was slightly more active than (5)-124. Further field tests suggest that there is an optimum R/S ratio of 95 5 for trapping of males.146... 

Predict the biosynthetic origin of a component of the sex pheromone of the tea tortrix moth below, by drawing its biosynthetic units in position. Careful, it can start with something larger than acetate or propionate ... 

The suggestion that the sex pheromone composition of the oak leaf roller was dependent to a large extent on diet was made 82,475,476) and refuted 477, 478). It is now generally accepted that the sex pheromone of this tortricid moth species is a specific blend (67 33) of E)- - and (Z)-ll-tetradecenyl acetates 477). It is also accepted that in this species this ratio is not influenced by diet 478). However, the effects of diet on the amount of pheromonal compounds have been suggested for the summer fruit tortrix moth 479), the gypsy moth 480) and the smaller tea tortrix moth 481). 

SuGiE, H., S. Yamazaki, and Y. Tamaki On the origin of the sex pheromone components of the smaller tea tortrix moth, Adoxophyes fasciata Walsingham (Lepido-ptera Tortricidae). Appl. Ent. Zool. 11, 371—373 (1976). 

Contrary to the structure similarity of the pheromones secreted by taxonomical related moths, some differences are necessary for their sexual communication systems to play an important role in their reproductive isolation. In addition to further modifications of the various structures, diversity of the lepidopteran sex pheromones is generated by blending multiple components. Innumerable pheromone blends are based not only on combinations of different components but also on variations in the mixing ratio. A pioneer study with Adoxophyes spp. (Tortricidae Tortricinae) had already proposed this concept in the early 1970s. While the smaller tea tortrix (A. honmai) and the Japanese summerfruit tortrix (A. oranafasciata) had been considered to be variant strains with different host preferences in the same species, Tamaki et al. found that females of the former pest insect in the tea garden secreted Z9-14 OAc and Zll-14 OAc in a ratio of 7 4 but females of the latter defoliator of apple trees secreted them in a ratio of 13 4 [127,128]. Furthermore, two other components (Ell-14 OAc and MelO-12 OAc) were subsequently identified from the former species [129]. 

Lesser tea tortrix. A minor component of the sex pheromone blend of this moth is 10-methyl-l-dodecanol acetate, V, (Figure 10) (48). Mori has synthesized the enantiomers both compounds were constructed from (R)-(+)-citronellol (49). The racemic target compound was synthesized by alkylating 10-undecenoic acid (as its dianion) with ethyl iodide (50). Reduction of the carboxyl to a methyl group was accomplished by standard procedures. Hydroboration of the olefinic link with disiamylborane and oxidative workup yielded the primary alcohol which was then acetylated to give the racemic pheromone structure. The overall yield from undecenoic acid was 40-45% without any extensive effort to optimize. 

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