- A General Approach to the Synthesis of Mono-olefinic Insect Sex Pheromones of Z- or E-Configuration
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A series of insect sex pheromones and structually related olefins have been synthesized with high stereoisomeric purity by two sequential cross-coupling reactions.Starting with (Z)- or (E)-1-bromo-2-phenylthioethene, (1) and (2), and Grignard reagents in the presence of nickel or palladium catalysts, two types of compounds have been prepared: (i) 1,2-dialkylethenes and (ii) alkenyl acetates.In the synthesis of Z-isomers, the first step involves a cross-coupling reaction of compound (1) with the appropriate Grignard reagent in the presence of a catalytic amount of .The second cross-coupling reaction is performed on the intermediate (Z)-phenylthioalkenes using a different Grignard reagent in the presence of (dppe=Ph2PCH2CH2PPh2) as a catalyst.In the synthesis of E-isomers both steps are cross-coupling reactions of Grignard reagents in the presence of as a catalyst, the first step involving compound (2) and the second step involving the intermediate (E)-phenylthioalkenes obtained.The Grignard reagents used in the synthesis of the alkenyl acetates derive from protected ω-halohydrins.
- Fiandanese, Vito,Marchese, Giuseppe,Naso, Francesco,Ronzini, Ludovico
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p. 1115 - 1120
(2007/10/02)
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