| 摘要 |
A process is disclosed for preparing aliphatic compounds containing two conjugated double bonds cis-cis or cis-trans, characterized in that a compound of the general formula <IMAGE> (I) (in which R is H, alkyl from C1 to C10, or OY in which Y is a protective group selected from the class consisting of tetrahydropyranyl and 1-ethoxyethyl; X is an ester function selected from the class consisting of the acetates) is reacted with an alkyl-magnesium halide of the general formula: Z-Mg-R1 (II) (in which Z is chlorine, bromine or iodine, and R1 is a C1-C10 alkyl group, or a group (CH2)n OY in which Y has the same meaning as in formula (I), and n is a number from 3 to 10) in the presence of Li2CuCl4, CuCl, CuBr, or CuI at temperatures ranging from about -30 DEG to +10 DEG C. in the presence of ethyl ether or tetrahydrofuran as solvent, to obtain an aliphatic compound of the general formula: R-CH2-C 3BOND C-CH=CH-CH2R1 (III) in which the carbon atoms linked with the double bond carry two hydrogen atoms in cis position, and reducing the triple bond of (III) with lithium-aluminum hydride to produce the trans-cis compound, or reducing (III) with dialkylborane or catecholborane to produce the cis-cis compound. |
