Anion relay chemistry (ARC), an effective, multicomponent union tactic, was successfully employed for the total synthesis of the highly cytotoxic marine macrolide (−)-mandelalide A (1). The northern hemisphere was constructed via a new type II ARC/CuCN cross-coupling tactic, while the southern hemisphere was secured via a highly efficient four-component type I ARC union. Importantly, the synthesis of 1 showcases ARC as a rapid, scalable coupling strategy for the union of simple readily available building blocks to access diverse complex molecular fragments with excellent stereochemical control.

Stitching alkynes into bryostatin 3: The bryostatin family of marine natural products has been explored for a wide variety of pharmaceutical applications but remains challenging to source. The general structure comprises a macrocycle that contains three smaller, six-membered rings. Bryostatin 3 is distinguished by the added complexity of a fourth, fused lactone ring. Trost et al. report a convergent synthesis of this complex molecule, taking advantage of alkyne coupling reactions to stitch together three main fragments and asymmetric dihydroxylation and propargylation reactions to set stereochemistry. Science , this issue p. 1007