Aldehydic pheromone components production

Fig.i General biosynthetic pathways for the production of alcohol, aldehyde, and acetate ester pheromone components in female moths. Top production of saturated fatty acids. Middle production of monounsaturated fatty acids and limited chain shortening produces intermediate compounds that can be reduced to an alcohol. Aldehyde and acetate ester pheromones are produced by an oxidase and acetyl-transferase, respectively. Bottom biosynthetic pathway for the production of the acetate ester pheromone components in the cabbage looper moth, Trichoplusia ni. The CoA derivatives are reduced and acetylated to form the acetate esters. Additional pheromone components include 12 OAc and ll-12 OAc... 

Production of acetate ester pheromone components utilizes an enzyme called acetyl-CoA fatty alcohol acetyltransferase that converts a fatty alcohol to an acetate ester. Therefore, alcohols could be utilized as substrates for both aldehyde and acetate ester formation. In some tortricids an in vitro enzyme assay was utilized to demonstrate specificity of the acetyltransferase for the Z isomer of ll-14 OH [66]. This specificity contributes to the final ratio of... 

In summary, the pheromone blends produced by Heliothis species are generated by a common biosynthetic scheme which permits modifications that result in the production of species specific blends of pheromone components. Pheromone mediated reproductive isolation between H. zea and the other two species results from the fact that H. zea does not produce fourteen carbon aldehydes. 

R,6R) diastereoisomer (Scheme 7). Again, from 34 the (5R,6R) product 43 was obtained. Products 42 and 43 represent the two enantiomers of the proposed major component of a mosquito oviposi-tion attractant pheromone (18). The enantiomeric forms of 5-hexadecanolide, 44 and 45, the pheromone of Vespa orientalis, were obtained from the enantiomeric aldehydes 34 and 37 (19). All the compounds obtained up to this point have been prepared in both enantiomeric forms, starting from a single chiral material. 

The Norrish Type I fragmentation of the cyclic ketone (178) has been used in a synthesis of grandisol (179), a major component of the male boll weevil pheromone.125 The cleavage reaction gave the aldehyde (180) which was subsequently decarbonylated to give the desired product. 

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