Total Synthesis and Biological Evaluation of Rakicidin A and Discovery of a Simplified Bioactive Analogue

We report a concise asymmetric synthesis of rakicidin A, a macrocyclic depsipeptide that selectively inhibits the growth of hypoxic cancer cells and stem‐like leukemia cells. Key transformations include a diastereoselective organocatalytic cross‐aldol reaction to build the polyketide portion of the molecule, a highly hindered ester fragment coupling reaction, an efficient Helquist‐type Horner—Wadsworth—Emmons (HWE) macrocyclization, and a new DSC‐mediated elimination reaction to construct the sensitive APD portion of rakicidin A. We further report the preparation of a simplified structural analogue (WY1) with dramatically enhanced hypoxia‐selective activity.