Unified total synthesis, stereostructural elucidation, and biological evaluation of sarcophytonolides

Sarcophytonolides are cembranolide diterpenes isolated from the soft corals of genus Sarcophyton since 2005. Herein, unified total synthesis of sarcophytonolides C, E, F, G, H, and J and isosarcophytonolide D is reported. The key transformations in the synthetic route are fragment coupling, alkoxycarbonylallylation, macrolactonization, and transannular ring - closing metathesis. These total syntheses resulted in the absolute stereochemical confirmation of sarcophytonolide H, determination of sarcophytonolides C, E, F, and G, and revision of sarcophytonolide J and isosarcophytonolide D. We also evaluated the antifouling activity and toxicity of the synthetic sarcophytonolides H and J and their analogues as well as the cytotoxicity of the synthetic sarcophytonolides and their key synthetic intermediates.