Peach twig borer

E)-5-decenyl acetate CH3(CH2)3CH=CH(CH2)4OOCCH3 peach twig borer, Anarsia Hneatella (with (E)-5-decenol)... 

The CM of fatty acids and derived compounds also has been used for the production of fine chemicals that are difficult to obtain by other synthetic approaches. Some examples include the synthesis of a plant growth stimulant, an insect pheromone precursor, the sex pheromone of the peach twig borer moth, and others [28]. Furthermore, the conjugation of fatty acid derivatives, sugars, and amino acids via CM was shown by Vemall and Abell [41]. C4 with a catalyst loading of 20 mol% was used to perform the CM of either Ai-Boc-L-ly sine or N-Boc-L-cysteine bearing a 10-undecenoic chain with methyl 10-undecenoate or a sugar olefin. 

Olefin metathesis can be very useful in the CM mode, as shown in the synthesis of insect phere-mones.46 In the first example for the synthesis of the peach twig borer pheromone 23, an excess of 1-hexene was used to increase the yield of the desired product. However, both of the other products could be recycled (Scheme 28.17). In the second example, CM was used to change the ester groups of meadowfoam oil (24) through cleavage of the alkenes rather than ester bonds. The sequence resulted in the synthesis of the mosquito pheromone (25) (Scheme 28.18). 

Production of Materia 5-decene and 1,10- peach twig borer pheromone (5-decenyl Ruthenium based catalysts ... 

Figure 7 Synthesis of 5-decenyl acetate, a key component of the peach twig borer pheromone.

Although the desired product is often produced in low yield, cross metathesis does not result in the loss of double bonds, and the olefin fragments remain intact hence, the byproducts can be recycled. Recycling is demonstrated in the application below, where cross metathesis is used to prepare an insect pheromone for the peach twig borer, an insect that attacks a variety of fruits (Eq. 6.15). The pheromone can be used to control the population of the insect through disruption of the insect s mating process [35]. 

Wilting plus a gummy exudate from twigs may indicate peach twig borers. This pest also damages fruit. The second generation of these brown, /z" caterpillars tunnels into fruit, usu-... 

Peach aphids, green, 269,419 Peach leaf curl, 344,383 bordeaux mix for, 467 copper for, 471 peach and, 165,167,383 Peach rosette, 168,394,394 Peach scab,165,166 Peachtree borers, 313.313 apricot and, 27 cherry and, 69 peach and, 165, 168 pheromone traps for, 437 Peach twig borers almond and, 17 apricot and, 26 peach and, 165, 166-67 Pear, 168-71... 

Pheromones are chemicals that are used by animals and plants for communication. Insects utilize pheromones extensively to indicate their availability for reproduction, to sound alarms, and to make known the presence of food. The use of pheromones in small amounts in traps can interfere with the reproduction of harmful insects in an environmentally friendly manner. Recently, Grubbs second-generation catalyst (24) was used to synthesize on an industrial scale the sex attractant pheromone of the peach twig borer, a pest that attacks peach, plum, nectarine, and almond crops.46 Equation 11.16 shows how Ru-catalyzed metathesis of 5-decene and l,10-diacetoxy-5-decene produces a 50% yield of E-Z mixture (the desired E-isomer predominates, and the presence of small amounts of Z-isomer does not lower the activity of the pheromone) of the desired pheromone at low temperature. The unreacted starting materials are recovered by vacuum distillation and recycled. 

Peach twig borer moth (Anarsia lineatella)... 

The Peach twig borer (Anarsia lineatella) is a moth conunonly found in Europe, but was introduced to California in the 1880s (Fig. 8.80). It is a significant pest of peach, nectarine and apricot orchards and also of local almond plantations. [185]... 

Another example of organic synthesis via cross-metathesis is the synthesis of biologically active compounds such as insect pheromones. Use of such pheromones offers an effective and selective pest control method. Thus, cross-metathesis of ethyl oleate with 5-decene results in a cis-trans mixture of ethyl 9-tetradecenoate, an insect pheromone precursor [15]. Cross-metathesis of methyl d.y-5-eicosenoate (obtained from meadowfoam oil) with excess 5-decene gives methyl tm 5-decenoate, which can be transformed into a 83 17 mixture of trani -5-decenylacetate and tran.y-5-decenol (in total 90% trans), the sex pheromone of the Peach Twig Borer moth, a major pest in Northern Hemisphere fruit orchards. The isomeric mixture was active in mating disruption [16]. Other examples of organic synthesis via cross-metathesis are summarised elsewhere [17 18]. 

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