Stereocontrolled Total Synthesis of Lipoxins As and B₅

Icosapentaenoic acids and their metabolites are of both nutritional and bio‐medical interest. The title compounds were previously accessible in only very small amounts via biosynthetic routes. Their first total synthesis has now been achieved in good yield and in a stereocontrolled fashion. The key steps were a Pd⁰–Cu¹‐catalyzed coupling of terminal alkynes with vinyl halides to give the icosanoid skeleton and Lindlar hydrogenation to give the Z olefins. (Figure Presented.)