Red bollworm moth

In addition to the synthetic applications related to the stereoselective or stereospecific syntheses of various systems, especially natural products, described in the previous subsection, a number of general synthetic uses of the reversible [2,3]-sigmatropic rearrangement of allylic sulfoxides are presented below. Several investigators110-113 have employed the allylic sulfenate-to-sulfoxide equilibrium in combination with the syn elimination of the latter as a method for the synthesis of conjugated dienes. For example, Reich and coworkers110,111 have reported a detailed study on the conversion of allylic alcohols to 1,3-dienes by sequential sulfenate sulfoxide rearrangement and syn elimination of the sulfoxide. This method of mild and efficient 1,4-dehydration of allylic alcohols has also been shown to proceed with overall cis stereochemistry in cyclic systems, as illustrated by equation 25. The reaction of trans-46 proceeds almost instantaneously at room temperature, while that of the cis-alcohol is much slower. This method has been subsequently applied for the synthesis of several natural products, such as the stereoselective transformation of the allylic alcohol 48 into the sex pheromone of the Red Bollworm Moth (49)112 and the conversion of isocodeine (50) into 6-demethoxythebaine (51)113. 

Much less has been done with the functionalized halides than with the functionalized olefins. The only two-carbon compound in this group is vinyl bromide (or iodide). This is a very useful reactant with secondary amines because terminal allylic amines are usually major or exclusive products. We have used this halide for synthesizing the pheromone of the Red Bollworm Moth, 9,11-docecadien-l-ol as follows (9). Of the four three-carbon functionalized vinylic halides listed,... 

E)-l,3-Dienes, (E,E)-conjugated dienes. Metallation and alkylation of 1 results in a single product fonned by exo-attack. Thermolysis of the product results in a terminal (E)-l, 3-diene. An example is the synthesis of 2, a sex pheromone of the red bollworm moth. 

The Pd-catalyzed elimination reaction was applied to the synthesis of 12-acetoxy-l,3-dodecadiene, an insect sex pheromone from the red bollworm moth, by elimination of phenol with Pd(OAc)2 and P(OPh)3 at 160 °C under reduced pressure (1 torr) from the allyl phenyl ether prepared from a butadiene telomer (Scheme... 

Tricarbonyliron diene complexes have been used in a simple stereospecific synthesis of insect pheromones. The basis of this synthesis relies on the Friedel-Crafts acylation of various diene complexes. The strategy is illustrated with a preparation of the pheromone (7) from the red bollworm moth (Scheme 29). 

A number of conjugated dienes have been identified as sex pheromones. Among these are (8 ,10 )-8,10-dodecadien-l-ol (475, Scheme 84) from the codling moth (Laspeyresia pomonella), (7 , 9Z)-7,9-dodecadien-1-yl acetate (490, Scheme 86) from the European grapevine moth (Lobesia botrana), ( )- and (Z)-9,ll-dodecadien-l-yl acetates (518a and 518b, respectively, see Scheme 90) from the red bollworm moth (Diparopsis castanea), and (10 , 12Z)-10,12-hexadecadien-l-ol (498, Scheme 87) from the silkworm moth (Bombyx mori). 

Nesbitt, B. F., P. S. Beevor, R. A. Cole, R. Lester, and R. G. Poppi Synthesis of both geometric isomers of the major sex pheromone of the red bollworm moth. Tetrahedron Lett. 1973,4669—4670. 

Mori, K. Simple synthesis of sex pheromones of codling moth and red bollworm moth by the coupling of Grignard reagents with allylic halides. Tetrahedron 30, 3807—3810(1974). 

Tertiary pheromonal blends have been identified in two noctuid moths. The red bollworm, Diparopsis castanea, emits dodecyl acetate, (E)-9-dodecenyl acetate, 11-dodecenyl acetate, and (E)-9,ll-dodecadienyl acetate as a sex pheromone, whereas Spodoptera littoral is utilizes a blend made up of tetradecyl acetate, (E)-9-tetradecenyl acetate, (E)-ll-tetradecenyl acetate, and (Z,E)-9,ll-tetradecadieny1 acetate (89). For both species, the conjugated dienes are the most potent olfactory stimulants. 

Insecticides Vetch aphid (Megoura viciae) bollworm (Helicoverpa zea) army worm (Spodoptera littoralis) diamondback moth (Plutella xylostella) mustard beetle (Phaedon cochleariae) corn rootworm (Diabrotica undecimpunctata) whitefly Bemisia tabaci) red spider mite (Tetranychus urticae). 

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