Abstract

New degraded and rearranged diterpenoids, 5-8, have been isolated from the Antarctic sponge Dendrilla membranosa. The structure and relative stereochemistry of these compounds were determined by spectroscopic data. The absolute stereochemistry of 5 was determined by spectroscopic data using a chiral reagent. Conformational studies allowed us to assign also the absolute stereochemistry of 6-8, as well as those previously isolated spongian-derived metabolites with known relative stereochemistries. © 2003 Elsevier Ltd. All rights reserved.