Synthesis of Two Intermediate Phosphonium Salts for 5,20 and 15,20-DiHetes

Abstract

In the past decade, a wide variety of oxygenated metabolites of arachidonic acid have been isolated¹. Most of them exhibit potent biological activity and some were also synthetized both to assess their stereochemistry and to get sufficient amounts for biological testing². In addition to the well-known cyclooxygenase and lipoxygenase pathways, another type of metabolism was observed. NADPH dependent monooxygenation catalyzed by cytochrome P-450 induces three types of primary oxidation reactions: (a) olefin epoxidation (epoxygenase) generating four regioisomeric epoxyeicosatrienoic acids (EETs)³, (b) allylic oxidation resulting in six regioisomeric cis, trans-conjugated hydroxyeicosatetraenoic acids (HETEs), and (c) hydroxylation of an unactivated sp3 carbon (ω/ω 1 oxygenase)⁴.