Synthetic Studies on the Sporolides : Exploration of the Enediyne Route

Synthetic studies towards the construction of the cyclopenta[a]indene fragment of the heptacyclic marine metabolite sporolide are reported based on a hypothetical biosynthesis. The key step of this biogenetic proposal includes a Bergman cyclization of an enediyne precursor. The enediyne target of this synthetic study was prepared by Sonogashira cross-coupling of two fragments, of which the cyclopentane fragment was prepared from cyclopentenone, Morita-Baylis-Hillman reaction, and enantioselective Sharpless dihydroxylation.