Total Synthesis of(+)-Exiguolide

摘要

Exiguolide(1)is a unique 16-membered macrolide isolated from the marine sponge Geodia exigua Thiele(order Astro-phorida,family Geodiidae).It specifically inhibits fertilization of sea urchin {(Hemicentrotus pulcherrimus)gametes but not embryogenesis of the fertilized egg.The macrolide structure incorporates two cis-2,6-disubstituted oxane rings,one of which carries an exocyclic enoate appendage reminiscent of bryostatins.The unique structural features and interesting biological activity of 1 has generated considerable interest in this compound,and herein we report our recent results for the total synthesis of 1.