Acknowledgment. The syntheses of 5 and 8 were un- dertaken as a direct result of discussions with M. Potter and DM Segal, respectively, during which discussions, general structural requirements were posed. The assis- tance of JJ Moore in the preparation of 8 is appreciated. ... S. Stoney Simons, Jr.,* Michel Pons,$ and David F. Johnson ... Laboratory of Chemistry, National Institute of Arthritis, Metabolism and Digestive Diseases, National Institutes of Health, Bethesda, ...