Stereoselective Synthesis of ABC-Ring System of Hemibrevetoxin B

Abstract

Abstract The 6, 6, 7-membered tricyclic ether ring system (ABC-ring) of hemibrevetoxin B was stereoselectively synthesized. The curcial steps in the present synthesis involve the ring expansion of tetrahydropyran to oxepane, 6-endo cyclization of epoxy alcohol, and insertion of a C-4 unit to the A-ring.