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
We have developed an efficient and highly stereocontrolled synthesis of bistramide A, a selective activator of protein kinase C isotype delta. Our synthetic strategy featured a novel bidirectional approach for spiroketal construction based on the ring-opening/cross-metathesis sequence employing a highly strained cyclopropenone acetal. The synthesis afforded the final target with the longest linear sequence of 15 steps and provided unambiguous structural determination of bistramide A, including assignment of the previously unknown C(37) stereochemistry.