Latest Research Discoveries | Yefeng TANG and Gang LIU publish "Total Syntheses of Asperchalasines A-E" in Angew. Chem. Int. Ed.

The first total syntheses of asperchalasines A‐E, a collection of unprecedented merocytochalasans, are reported. Aspochalasin B, a key tricyclic cytochalasan monomer, was first synthesized through a unified approach that hinges on a Diels‐Alder reaction and an RCM reaction. The bioinspired Diels‐Alder reactions of aspochalasin B with different epicoccine precursors were then explored, which enabled the divergent access of the hetero‐dimers asperchalasines B‐E as well as related congeners. Furthermore, the hetero‐trimer asperchalasine A was obtained from one epicoccine unit and two aspochalasin B units through a biomimetic Diels‐Alder reaction followed by an oxidative [5+2]‐cycloaddition.