RADIOSYNTHESIS OF 1-[C-11] POLYHOMOALLYLIC FATTY-ACIDS

A facile retro-synthesis involving the radical chain decarboxylation of the N-hydroxypyridine-2-thione esters of both arachidonic and docosahexaenoic acid was utilized to synthesize (all Z)-1-bromononadeca-4,7,10,13-tetraene, and (all Z)-1-bromoheneicosa-3,6,9,12,15,18-hexaene in 60% overall yield. The corresponding polyhomoallylic magnesium bromides were carbonated with [C-11]CO2 to afford the 1-[C-11]polyhomoallylic labeled fatty acids in good yield in less than 35 minutes. The final radiochemical purities were found to be in excess of 95% by radio-HPLC.