Moth pheromones synthesis

Commercial synthesis of the gypsy moth pheromone (7R,SS)-d sparlure by J. T. Baker ... 

It should be added that many other groups have contributed to the predevelopments of these inventions and also to later developments. All four reactions find wide application in organic synthesis. The Sharpless epoxidation of allylic alcohols finds industrial application in Arco s synthesis of glycidol, the epoxidation product of allyl alcohol, and Upjohn s synthesis of disparlure (Figure 14.4), a sex pheromone for the gypsy moth. The synthesis of disparlure starts with a Ci3 allylic alcohol in which, after asymmetric epoxidation, the alcohol is replaced by the other carbon chain. Perhaps today the Jacobsen method can be used directly on a suitable Ci9 alkene, although the steric differences between both ends of the molecules are extremely small ... 

This catalytic epoxidation method has been applied to the synthesis of a variety of natural products, particularly polyhydioxylated compounds, including carbohydrates (54) and macrolides. In addition, this reaction has been used for commercial synthesis of disparlure, a gypsy moth pheromone [J. T. Baker Co. (55) and the Shanghai Institute for Organic Chemistry (56)], and more importantly, glycidol, a versatile intermediate for synthesis of /3-blockers and other functionalized chiral molecules (Arco Co.) (Scheme 23) (57). 

Brevet, J.-L. and Mori, K. (1992). Pheromone synthesis CXXXIX. Enzymatic preparation of (2S,3R )-4-acetoxy-2,3-epoxybutan- l -ol and its conversion to the epoxy pheromones of the gypsy moth and the ruby tiger moth. Synthesis, 1992, 1007-1012. 

Mori, K. and Ebata, T. (1981). Synthesis of optically active pheromones with an epoxy ring, (+)-disparlure and the saltmarsh caterpillar moth pheromone (Z,Z)-3,6-d.s-... 

Enzyme-Catalyzed Pheromone Synthesis by Heliothis Moths... 

In a demonstration of the synthetic utility of chiral y-alkoxy stannane reagents, Marshall and co-workers applied this methodology to the synthesis of the gypsy moth pheromones (+)- and (-)-disparlure [287]. The synthesis required the production of the [y-(alkoxy)allyl]stannane reagent 440 (Scheme 11-32). 

The last decade has witnessed the application of 1-halogenoacetylenes as crucial intermediates for the synthesis of increasingly complex structures, especially in natural product chemistry. In pheromone synthesis it is essential to create double-bond systems diastereoselec-tively, and a route often taken consists in the preparation of a suitable alkyne precursor which is then converted into the final olefin by various addition reactions (catalytic hydrogenation, metalation, etc.). For the construction of the alkyne precursor to the pheromone, 1-bromo-(94) and 1-iodoalkynes (95) have been particularly valuable since they can easily be subjected to metal-catalyzed coupling reactions [105]. For ocample, the unsaturated ester 163, which is a sex attractant of Lepidoptera (moths and butterflies), has been prepared by first converting the terminal acetylene 160 into its 1-iodo derivative 161. This is subsequently hydrogenated... 

An example of the stereoselective formation of ( )-dienes was the synthesis of a red bullworm moth pheromone (160). Sulfolene (159) was available from 3-sulfolene by selective alkylation, and on heating gave diene (160) as a single isomer [116,117] (Scheme 6.51). 

As far as we know, there are only four publications devoted to cometathesis of COD with 1-hexene for pheromone synthesis of pink bollworm moth Pectinophora gossypiella) [31-34]. In 1973 Hammel et al recognized that a sex pheromone of this pest is a blend of 7Z,1 IZ-hexadecadienyl acetate and its corresponding Z,E-isomer [35]. It was shown later that the isomer ratio produced by the insect females depends on the geographic area of habitants. As a rule the natural content of Z,Z-isomer is about 56-62% [36-38]. Haynes et al found that the effectiveness of the action of artificial sex... 

There has been a further carbohydrate-based synthesis of the epoxide (+)-disparlure, the gipsy moth pheromone, using 2-deoxy-D-ribose as starting material and epoxyalcohol intermediates. (14S, 15S)-Leukotriene A4 methyl ester (58) has been prepared using the synthon (57), derived from D-glucal, as precursor, and epoxy alcohols were again used as intermediates. A synthesis of (+)-muscarine (59) from L-rhamnose is outlined in Scheme 10.46... 

The potential of dihydro-oxazines is displayed to advantage in a high-yield synthesis of the male bollworm moth pheromone, tra/w-l-acetoxy-10-n-propyltrideca-5,9-diene. Alkylation of anions from dihydro-oxazines with a,o)-dihalogenoalkanes and subsequent elaboration of the terminal halide provides a route to variously functionalized aldehydes (Scheme 63). 

SCHEME 42.29. Synthesis of moth pheromones 107 and 108 using asymmetric organocatalytic a-chlorination. 

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