Efforts Toward the Total Synthesis of Bielschowskysin

Abstract

The furanocembranoids are a family of natural products generated from oxidation and polycyclization of well-established terpene frameworks. The biosynthesis of these metabolites involves oxidative installation of butenolide and furan functionality from cembrane. Transannular cyclization produces complex heterocycles Bielschowskysin is a hexacyclic furanocembranoid isolated from the Caribbean gorgonian octocoral Pseudopterogorgia kallos by Rodriguez and coworkers in 2004. Its novel tetradecane ring system incorporates eleven stereocenters (seven contiguous). Additionally, the metabolite was shown to exhibit antimalarial activity against Plasmodium falciparum (IC50= 10 µM); as well as strong anticancer activity against small cell lung cancer (GI50 < 0.01 µM), and renal cancer (GI50 < 0.51 µM). Owing to its intriguing architecture and therapeutic properties, we are currently exploring a route toward the synthesis of this diterpene incorporating a stereoselective [2+2]-photocyloaddition and vinylogous intramolecular aldol reaction as key steps.