Stereochemistry of antiinflammatory marine sesterterpenes

The absolute configuration of antiinflammatory marine sesterterpenes belong ing to the manoalide and cacospongionolide structural type has been determi ned by comparison of the CD spectra of the natural compounds with those of analogues that have been stereoselectively synthesized. In the derived acet ates the relative stereochemistry of the stereogenic centres in the pyranof uranone moiety is assigned from H-1-NMR data and the absolute configuration from CD spectra. The absolute configuration of the naturally occurring mar ine sesterterpenes thorectolide monoacetate, manoalide monoacetate, petrosa spongiolide M and cavernosolide has been determined.