Synthesis of very long chain fatty acid methyl esters

Abstract

Phosphoranes, produced by treating alkyltriphenylphosphonium bromides with lithium hexamethyldisilazide, reacted with ω-oxo esters to give modest yields of the corresponding methyl cis-alkenoates. By an alternative method, treatment of ω-iodo esters with the complexes formed from reactions of alkylcopper(I) and Grignard reagents gave methyl alkanoates. cis-alkenoates, and methylene- interrupted cis,cis-alka-dienoates and cis,cis,cis-trienoates. The stereochemical integrity of the esters was determined by ¹³C NMR spectroscopy.