39836-21-0

Fatty acid derived carboxylic acids with double bonds, hydroxy-, amino-, keto-, ester- and epoxy groups are anodically coupled to dimers (Kolbe electrolysis) in 29 to 81% yield and up to a 2.5 mol scale. Problems due to the low conductivity of fatty acid salts were overcome by the use of a flow cell with a narrow electrode gap. Fatty acids with branched alkyl chains gave dimers with interesting emulsifying properties. Dimethyl hexadecanedioate, accessible from methyl azelate, could be cyclized and further converted into homomuscone and muscone in a few steps. A commercial mixture of dimeric fatty acids (C36-dicarboxylic acids) has been coupled to give C70-diesters. Acta Chemica Scandinavica 1998. Part 64: Nielsen, M. F., Batanero, B.,.

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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.

A process for the preparation of a straight-chain or branched alkene which has 20 to 24 carbon atoms and in which the ethylenic bond is located after a carbon atom numbered between 8 and 11, which process comprises reacting, in an anhydrous solvent, preferably in an oxahydrocarbon an organometallic copper compound with an alkyl or alkenylsulfonate.