Synthesis of omega 9-tetracosynoic and omega 9-octacosynoic acids as entries into tritiated metabolic precursors of cis-9-tricosene and cis-9-heptacosene in the housefly.

The syntheses of 15-tetracosynoic acid (omega 9-tetracosynoic acid) and 19-octacosynoic acid (omega 9-octacosynoic acid) are described. These alkynoic acids are to be tritiated to the corresponding alkenoic acids, which will be used as metabolic precursors of housefly pheromone components. The final step in each synthesis involved the coupling of 1-decyne to the lithio-salt of the appropriate omega-bromoacid. Homologation of dibromoalkanes was accomplished with triphasic catalytic displacement of bromide by cyanide ion. Oxidation of a bromo-alcohol to a bromoacid was performed in benzene with KMnO4 and 18-crown-6 ether.