Structure and Synthesis of Active Component From a Marine Alga, Sargassum Tortile, Which Induces the Settling of Swimming Larvae of Coryne Uchidai

Based on the observation that the juice of yoremoku induces the settling of swimming larvae of Coryne Uchidai, we searched the active component in the alga by means of bioassay using the swimming larvae and elucidated the structure of the active principle to be 1 and 2. The structure was unequivocally confirmed by synthesis and (±)-epoxide (2) exhibited the clear activity toward the settling of swimming larvae.