New Diterpenes from the Common Caribbean Gorgonian Briareum asbestinum (Pallus)

Article abstract of DOI:10.1021/jo00318a023

The major diterpenes in the toxic extracts of Briareum asbestinum (Pallus) from three Honduras Bay Island collections are reported.The structure and chemistry of two new asbestinins, 2 and 3, and four known ones, 4, 5, 9,and 10, are discussed.Structures for 2 and 3 were derived from spectroscopic arguments and were confirmed by chemical interconversions.NMR experiments including 13C at 90 MHz, a plot of J_R/J_CH with δ_H , and 1H spin decouplings at 360 MHz enabled assignment of all 26C's and 40 H's in 4.These data served as a standard to completely assign the 1H and 13C NMR for natural products 2, 3, 5, 9, and 10 and for synthetic products 6 and 7.