Marine Terpenes and Terpenoids. III. Isolation and Structures of Two Cembrane Diols from the Soft Coral Sinularia mayi

Abstract

Nine cembrane-type diterpenes were isolated from the lipid extract of the soft coral, Sinularia mayi. Of these, seven α-methylene-γ-lactone derivatives (1-7) had been previously isolated from various soft corals. The structures of the two new cembrane diols, sinulariol A (8a) and sinulariol B (9), were determined by means of spectroscopic analyses, and compound 9 was chemically correlated with nephthenol (11) whose absolute configuration is known. Compounds 8a and 9 are plausible precursors to the cembrane lactones found in various soft corals.