Synthetic Studies toward the Total Synthesis of Scabrolide A

Herein, we report a concise route to the [5-5-6]-fused tricyclic core of scabrolide A and our efforts toward the construction of the fourth cycloheptane ring of the molecule via a 7-endo-trig radical cyclization. The tricyclic cyclohexenone core was assembled by a ring-closing metathesis (RCM) reaction followed by oxidation and concomitant isomerization of the double bond. These promising results have potential implications in the synthesis of similar tricyclic cores of many other congeners within this family of furanobutenolide-derived polycyclic cembranoids and norcembranoids.