Synthesis of 2trans‐alkene‐mono‐and ‐poly‐ynoic acids with a triple bond in the 5‐position and their hydrogenation. A new synthesis of arachidonic acid

Abstract

2Trans-alkenoic, 2trans-alkenemonoynoic and 2trans-alkenepolyynoic acids with the first triple bond in the 5-position could be obtained in high yield by coupling I -alkyl-and 1 m o n o -or -poly-ynylmagnesium bromides with 4-bromocrotonic acid in tetrahydrofuran at low temperature.By hydrogenation in the presence of Lindlar's catalyst, CLY polyenoic acids with a 2frans double bond have been synthesized. On continued hydrogenation, the 2irans double bond can be removed selectively. This new method has been applied to the synthesis of 2frans,5cis,8cis,l lcis, 14cis-eicosapentaenoic acid and its hydrogenation to 5cis,8cis,ll cis,l4cis-eicosatetraenoic acid (arachidonic acid).

Full Library of (Bis–allyl)‐deuterated Arachidonic Acids: Synthesis and Analytical Verification

“…Typical approaches to the synthesis of isotopically substituted arachidonic acid are based on the use of the Wittig reaction, polyacetylene strategy (Scheme ), or combination of both . The Wittig reaction allows more precise control of the configuration of the double bonds created, but strongly basic conditions can cause isomerization of double bonds in the 1,4‐diene systems.…”