12-epi-Scalarin and 12-epi-deoxoscalarin, sesterterpenes from the sponge Spongia nitens

Abstract

Two minor terpenoid components of the Spongia pitens have been identified as the 12-epimers-of scalarin (1) and deoxoscalarin (2), members of a new sesterterpene class recently discovered in sponges. With the aid of circular dichroism, and 1H and 13C n.m.r. spectroscopy, total stereochemistry has been assigned to the new compounds and their epimers.