10- Undecen

PREPARATION OF ALKENES BY REACTION OF LITHIUM DIPROPENYLCUPRATES WITH ALKYL HALIDES ( )-2-UNDECENE... 

Yields of (.E)-2-Undecene Prepared from 1 Equivalent of the indicated Substrates by Reaction Either with 1 Equivalent of Lithium Diproprnyxcuprate or 1 Equivalent of Propenyllithium... 

Unreacted chloride remains at the end of the roaetion (with R2CuLi 15%, with RLi 40%) 1.5 equivalents of R2CuLi per equivalent of chloride givos 95% (. /)-2-undecene after 5 days at 25°. e A volumo of THF equal to that of the ether present was added after formation of the cuprate was complete. THF tetra-hydrofuran HMPA hexamethylphosphoric triamide EtaO diethyl ether DME 1,2-diinethoxyethane. 

NonenaL 2-decenal and 2-undecenal were concentrated appreciably in fraction FI of the 207 bar/50°C extract, whereas aldehydes associated with lipid oxidation such as pentanaL hexanal and octanal were not concentrated by the extraction method used, probably because these constituents continue to accumulate following extraction or because low volatiles are not extracted well by the SC-COj method used. 

A study using triolein under the same conditions produced seven major volatile compounds from oleate (heptane, octane, heptanal, octanal, nonanal, 2-decenal, and 2-undecenal) as well as other minor components. Addition of stearate to the reaction substrate produced added volatiles previously identified as originating from tristearin alone (Selke et al., 1977). 

Aldehydes Hexanal, 2,4-Decadienal (EZ) Heptanal, 2,4-Decadienal (EE) 2-Nonenal, 2-Ethylhexenal 2-Hexenal, 2,4-Heptadienal 2-Undecenal, 2,4-Nonadienal 2-Heptenal, Nonanal, Decenal Decanal. 2-Octenal. Octanal CORC ++ Decadienal (EZDe) (RV = 0.991)... 

Z,5 )-3,5-Tetradecadienyl acetate 284 was recently presumed to be the pheromone of Prionoxystus robiniae on the basis of electronantennogram data it could be synthesized via Wittig reaction of ( )-2-undecenal 282 and the ylide 283. (3Z,5 )-3,5-tetradecadienyl acetate 284 was separated from its distillation residue [98% (3E,5E)-3,5-isomer] with 95 % purity by means of spinning ribbon-column distillation 196> (Scheme 52). 

The cross-coupling of allylsilanes with alkenes [50] and styrene [58] also occurs via their preliminary isomerization followed by the reaction of 1-propenylsilane with exemplary olefin-l-decene resulting in l-(triethoxysilyl)-1-decene as a product (Eq. 31). If the cross-coupling takes place, an expected product of this reaction is l-silyl-2-undecene, which is not detected. 

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