2 NEW SESTERTERPENES FROM A SOUTH CHINA SEA SPONGE

Two new scalarane derivatives, phyllactones F and G, have been isolate d from the sponge Phyllospongia foliascens. Compounds 1 and 2 are anom ers whose structures were determined on the basis of spectral data. Th e absolute stereochemistry of phyllactone B [6] has been established u sing Mosher's method, and this permitted verification of the assignmen ts of absolute stereochemistry for all scalarane sesterterpenes isolat ed from the Chinese sponge P. foliascens.