SYNTHESIS OF [18-C-11 (C-13)]LINOLEIC ACID

A method for the preparation of [18-C-11]linoleic acid is described. A highly reactive zerovalent copper complex was prepared from lithium ( 2-thienyl)iodocuprate reduced by lithium naphtalenide. This copper com plex was used in a coupling reaction between 17-iodo-cis,cis-9,12-hept adecadienoic acid tert-butyl ester and [C-11]methyl iodide to form [18 -C-11]linoleic acid tert-butyl ester as intermediate. The tert-butyl e ster protecting group was rapidly removed with trifluoroacetic acid, a ffording [18-C-11]linoleic acid in 48% radiochemical yield. In a typic al run starting with 27 GBq of [C-11]methyl iodide, 2.9 GBq [18-C-11]l inoleic acid was obtained within 44 min from the end of radionuclide p roduction.