Irregular cembranoids containing a 13-membered carbocyclic skeleton isolated from a soft coral, Sarcophyton species

The structures and absolute structures of three new 13-membered carbocyclic cembranoids, sarcotol (1), sarcotol acetate (2), and sarcotal acetate (3) from a soft coral, Sarcophyton sp. have been determined by spectroscopic and single crystal X-ray analyses, and chemical conversion. Ichthyotoxity tests were performed for 1, 2, 3, and their reduction products.