Dodecadiene-1-yl acetate

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 ... 

Dienes. Negishi and Abramovitch have found that reasonably hindered organoboranes are much more reactive to alkynyllithiums than an acetoxyl group is and have used this property for an efficient synthesis of (7E, 9Z)-dodecadien-1 -yl acetate, a sex pheromone of the European grapevine moth (equation I). 

The preparation of the sex pheromone of the bollworm moth, ( )-9,11-dodecadien- 1-yl acetate, from compound A has been described. Suggest suitable reagents for each step in this sequence. 

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). 

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.8 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- 1-yl acetate via the ate complex (Scheme 43). 

---