A synthon for C-20 trideuterated eicosanoids: Preparation of [2H3]-arachidonic acid

Starting from hex‐5‐yn‐1‐ol an efficient seven step synthesis of (Z)9‐[2H3](non‐3‐en‐1‐yl) triphenylphosphonium bromide is described. This Wittig reagent is a key intermediate for the synthesis of C‐20 trideuterated eicosanoids. Introduction of deuterium at C‐20 provides standards that are stable to a wide range of reagents and reaction conditions. The utility of the Wittig synthon was demonstrated by the preparation of C‐20 trideuterated arachidonic acid.