Insects, pheromones

Enantiomerically enriched formyl irimclhyleiiemethane -irontricarbonyl complexes add to allylzinc bromides with high stereoselectivity. This was used, after photochemical deprotection, in an enantioselcctive synthesis of the insect pheromone (-)-ipsdienol4s. 

Both chiral lactones and ketones have been utilized in asymmetric synthesis of bioactive compounds like lipoic acid [175[ and natural products like various insect pheromones [176[. 

Figure 10.33 Complementary, backbone-inverting approaches for the asymmetric synthesis of the insect pheromone (-l-)-exo-brevicomin.

Some insect pheromones are internal ketals. We have already mentioned multistriatin (pp T 2 and 99) and frontalin p 193). Brevicomin (22) is another example. Disconnection of the ketal gives (23) containing a 1,2-diol. Among other syntheses, hydroxy-lation of protected enone (24) by epoxidation and acid catalysed rearrangement gives brevicomin stereo-specifically,... 

The insect pheromone lineatin (21) contains a four-membered ring it also contains an acetal and disconnection of this reveals the carbon skeleton (22). Lineatin analysis... 

If the alkyne is hydroborated and then protonolyzed a Z-alkene is formed. This method was used to prepare an insect pheromone containing a Z-double bond. 

Four new or improved methods useful in the synthesis of aliphatic insect pheromones were reported. co-Bromo-l-alkanols are important building blocks in pheromone synthesis. Chong found that a,co-diols gave good yield of co-bromo-l-alkanols when heated with hydrobromic acid and toluene at reflux (Scheme 1) [10]. 

Mori K (1981) The synthesis of insect pheromones. In ApSimon J (ed) The total synthesis of natural products, vol 4. Wiley, New York, p 1... 

The variation of the chemical structures in both Type I and Type II compounds results from differences in both biosynthetic enzyme systems and their starting material. This topic, however, has been judiciously described in the chapter by R. Jurenka. While the grouping employed in this chapter is based on biosynthetic origin, some chemicals were involuntarily classified considering their functional groups more sizably than the origin. Incidentally, taxonomic information is important for insect pheromone research. In this chapter, the family name (with the common suffix -idae) is associated with the species name. For those species whose family name is not listed in Figs. 1 and 2, the superfamily name (with the common suffix -oidea) is associated. The subfamily name (with the common suffix -inae) is also described for the species in Tor-tricidae, Pyralidae, and Noctuidae. 

Ma PWK, Ramaswamy SB (2003) In Blomquist GJ,Vogt RG (eds) Insect pheromone biochemistry and molecular biology. Academic Press... 

Tumlinson JH,Fang N.Teal PEA (1997) In Carde RT, Minks AK (eds) Insect pheromone research new directions. Chapman 8c Hall, New York, p 54... 

Steinbrecht RA (2003) The 3rd International Symposium on Insect Pheromones, Backaskog Castle, Sweden... 

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