A SYNTHETIC APPROACH TO THE CIS-FUSED MARINE PYRANOPYRANS, (3E)-DACTOMELYNE AND (3Z)-DACTOMELYNE - X-RAY STRUCTURE OF A RARE ORGANOMERCURIAL

Investigations into the total synthesis of the unusual marine-derived pyranopyrans, the dactomelynes 1 and 2, are described. Present studies have led to the development of a scheme for procuring an appropriately functionalized bromine-containing pyranopyran 26. This intermediate was assembled by the application of the oxymercuration reaction to the olefinic alcohol 6. A single-crystal X-ray analysis has been obtained for the rare “basket-shaped” organomercurial 23b which served to define the stereochemistry of the tricyclic product 5. © 1990, American Chemical Society. All rights reserved.