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.