Stereoselective Chemoenzymatic Cascade Synthesis of the bis‐THF Core of Acetogenins

bis-Tetrahydrofuran acetogenins are a class of natural products displaying highly potent and selective anti-tumor activity. Herein we report a new route to precursors of these natural products, utilizing the pseudo C2-symmetry in the central bis-tetrahydrofuran fragment. Key steps of our stereoselective chemoenzymatic strategy include the epoxide hydrolase-mediated desymmetrization of meso-epoxides and a cascade cyclization in either “inside-out” or “outside-in” direction, providing stereoselective access to the cores of both bullatacin- and rolliniastatin 1-type acetogenins with 6 stereocenters each from a common mono-epoxide precursor.