9,11 -Dodecadien acetate

The preparation of the sex pheromone of the bollworm moth, ( )-9,ll-dodecadien-l-yl acetate, from compound A has been described. Suggest suitable reagents for each step in this sequence. 

Farnesyl, 10-bromo-10,l 1-dihydro-l 1-hydroxy-, acetate [2,6-Dodecadiene-1,11-diol, 10-bromo-3,7,11-trimethyl-, 1-acetate, ( , )-], 113 Ferrocene, 28... 

Hydroboration/protonolysis of ( )-enynes completes a route to (E, Z)-dienes. For example, the ( )-enyne generated in Figure B4.6 was converted into (IE, 9Z)-7,9-dodecadien-l-yl acetate (a natural sex pheromone of the European grape vine moth Lobesia botrana) by hydroboration with Sia2BH followed by acetic acid protonolysis (Equation B4.7). 

Dodecadiene derivatives were identified as sex attractants of Lasiocampidae species 168). While Canadian authors synthesized all four isomeric 5,7-dodecadiene alcohols, acetates and aldehydes by nonstereoselective Wittig reactions and subsequent isomer separation 197), Bestmann et al.198) described in a recently published... 

Many insect pheromones have conjugated cis, trans-diene system l52, l53). The versatility of these reactions is exemplified in the synthesis of many natural products l53-154, 55 In Eq. 99, the four step synthesis of a natural sex pheromone of the European grape vine moth (Lobesia botrana), (7E, 9Z)-7,9-dodecadien-l-yl acetate, is illustrated 155). 

Recently, Rossi et al. have applied the cross-coupling of 1-alkenylboranes with 1-alkynyl halides for the synthesis of natural products. Thus, (7 , 9Z)-7,9-dodecadien-1-yl acetate (32), the sex pheromone of Lobesia botrana, has been synthesized by the following sequence involving ... 

European grape vine moth (Lohesia botrana), IE, 9Z)-7,9-dodecadien-l-yl acetate, is illustrated... 

The theimolysis of 2-substituted 2,5-dihydrothiophene 1,1-dioxides leads to ( ) conjugated dienes via cycloieversion followed by the concerted cheletropic extrusion of sulfur dioxide. The thermolysis of the a, -alkylated sulfone (96) gives the intennediate, which loses SO2 to give 1-dodecadien-l-yl acetate (98), a component of the sex pheromone of the red bollwoim moth. Tliis procediue has been extended to the thermolysis of a,3-dialkylated sulfones in order to obtain ( , )-1,4-disubstituted-1,3-dienes (equation 46). Similar processes have been used for the syntheses of alkaloids. The synthesis of an Elaeocarpus alkaloid, elaeokwine A (100), makes use of the retrodiene extrusion of sulfur dioxide to give the 1,3-diene intermediate (99) that is subsequently consumed by an intramolecular imino DA reaction (equation 47). o-Xylylene (102) has been generated by rDA expulsion of SO2 from benzo-fiised 3,6-dihy(ho-l,2-oxathiin 2-oxide (101). ... 

Anion (64) generally reacts with carbonyl compounds at the y-position, whereas it reacts with alkyl halides at the a-position. The triethylaluminum ate complex of (64) exhibits reversed regioselectivity propanal and 2-methylpropanal give exclusively the a-adducts. The anti isomers are produced predominantly. Organic halides and trimethylsilyl chloride do not react with the aluminum ate complex. 9,11-Dodecadien-l-yl acetate, a pheromone of Diparopsis castanea, is prepared by condensation of 9-oxonon-l-yl acetate via the ate complex (Scheme 43). 

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