Pseudotrienic acid B lactone;(2R,7R,8S,13E,15E,17E)-2-[(2E,4E)-dodeca-2,4-dien-2-yl]-7-hydroxy-8-methyl-1-oxa-5,10-diazacyclononadeca-13,15,17-triene-4,9,19-trione
Jackpot: Two for one! Concise and highly convergent syntheses of the immunosuppressive agent FR252921 and the related antimicrobial natural product pseudotrienic acid B were achieved from one common intermediate by using optically active titanium complexes to control the configuration of the stereogenic centers, a highly stereo‐ and regioselective cross‐metathesis to generate the triene moieties, and