Studies toward the total synthesis of gambieric acids, potent antifungal polycyclic ethers: convergent synthesis of a fully elaborated GHIJ-ring fragment
A stereocontrolled synthesis of a fully elaborated GHIJ-ring fragment of gambiericacids, which are potent antifungal polycyclic ether natural products, has been accomplished. The synthesis features convergentassembly of the tetracyclic polyetherskeleton through aldol coupling/cyclodehydration/reductive etherification processes and stereoselective construction of the J-ring side chain by a CeCl3-promoted