Pheromone intermediates prepn. - by reaction of diene(s) or ene:yne(s) with Grignard reagent catalysed by copper salt

摘要

Conjugated dienes and ene-ynes of formula CR1R2=CR3CR4= CR5-CH2R6 (I) or CR1=C-CR4=CR5-CH2R6 (II) (where R1-5 are each H, alkyl, aryl, or aralkyl of 1-14C; R6 is straight or branched prim. -alkyl of 2-14C, which may be substd.), are prepd. by reacting an organomagnesium cpd R6MgX (X = anion) with a dienyl or ene-ynyl ether CR1R2=CR3-CR4=CR5CH2OR (III) or CR1=CR4=CR5CH2OR (IV), (where R is (ar)alkyl, aryl, trialkysilyl or an ether gp.) at ambient temp. and atmospheric pressure, in an anhydrous solvent, in the presence of a calytic amt. of Cu salt. Prods. are suitable as intermediates for the prepn. of the insect attractant pheromones. the preparation does not cause transposition and maintains the stereo-chemistry of the double bonds.