Synthesis of a proposed biosynthetic intermediate of a marine cyclic ether brevisamide for study on biosynthesis of marine ladder-frame polyethers

A monocyclic ether alkaloid, brevisamide ( 1 ) was isolated from the dinoflagellate Karenia brevis that produces a variety of ladder-frame polyethers. Its proposed biosynthetic intermediate ( 2 ) comprising a linear backbone with an E -olefin functionality was synthesized for biosynthetic studies on the marine ladder-frame polyethers.