Marine Terpenes and Terpenoids. XI. : Structures of New Dihydrofuranocembranoids Isolated from a Sarcophyton sp. Soft Coral of Okinawa

Abstract

The cembranoids of a Sarcophyton sp. soft coral, collected in Okinawa, were found to be composed predominantly of dihydrofuranocembranoid derivatives (2, 3, 5a, 6 and 7) together with a hydrocarbon cembrene C (1) and a lactonic cembranoid, sarcophytonin B (4). The major constituents sarcophytonin A (2), deoxosarcophine (5a), and sarcophytonin C (6) were shown to be mixtures having similar enantiomeric ratios. The structures of the new compounds (3, 4, 6 and 7) were derived on the basis of spectroscopic studies and chemical correlations. Compounds 3 and 7 were supposed to be artefacts derived from 5a or 6 (3), and from 5a (7) respectively.