Synthetic studies on maitotoxin. 3. Stereloselective synthesis of the BCDE-ring system

The stereoselective synthesis of the BCDE-ring system of maitotoxin has been accomplished through a two-directional strategy for the construction of polycyclic ether. The key reactions involve SMl(2)-induced double cyclization of a,beta-alkoxyacrylate and a double dihydroxylation for construction of the B- and E-rings.