Cembranoid diterpenes and a briarane diterpene from corals

Two new cembrane diterpenes (+)-polydactylide (1) and (+)-7 alpha, 8 beta-dihydroxydeepoxysarcophine (2) together with (+)-sarcophine (3) and (+)-sarcophytoxide (4) have been isolated from the soft coral Sinularia polydactyla. The new cembrane diterpene (-)-7 beta-hydroxy-8 alpha-methoxydeepoxysarcophine (5) has been obtained from the soft coral Sarcophyton trocheliophorum and the known briarane diterpene briaexcavatolide W (6) from the gorgonian coral Briareum sp. The structures were determined primarily by NMR spectroscopy. The assignment of NMR signals was performed by means of H-1-H-1 COSY, ROESY, HMQC and HMBC experiments.