Synthesis of ω-Unsaturated Acids

Article abstract of DOI:10.1021/jo00269a038

A short, high-yield method for the synthesis of ω-unsaturated acids have been developed that precludes any double-bond migration or hydrogenation.Key is the coupling reaction between Grignards of ω-unsaturated alkyl halides and the bromomagnesium salt of ω-bromo fatty acids.The reaction has been successfully extended to ω-bromo nitriles.The use of ω-chloro acids or α-bromo acids gives lower yields of heterocoupling products and substantial homocoupling.A catalyst study shows Li2CuCl4 to yield the most heterocoupling of several catalysts tried for the chloro acids, and Ni(II) or Cu(I) are best for the α-bromo acids.