Preparation of Deuterated Arachidonic Acid

It is reported preparation of [²H₈]arachidonic acid from the precursor tetraacetylene eicosatetraynoic procedures gave rise to substantial double-bond isomerization and isotopic scrambling, leading to mixtures that yielded after purification only small quantities of the desired product. This chapter presents new preparation of deuterated arachidonic acid. For preparation of [²H₈]arachidonate, round-bottom flask is charged with methyl [²H₈]arachidonate, dimethoxyethane, and LiOH. The mixture is flushed with N₂, then stirred at 60 ° under an N₂ atmosphere. The reaction mixture was diluted with aqueous hydrochloric acid and extracted with CH₂Cl₂. The organic extracts were combined, dried over Na₂SO₄, filtered, and concentrated under vaccuum. The residue is taken up in methanol and chromatographed on a Waters μBondapak. Fractions are collected, and an aliquot of each was counted. The arachidonic acid usually appeared in fractions 52-64, with 95% recovery of applied radioactivity.