Synthesis of Coronanes 22 and 23

This synthesis demonstrates the plug-in Chime, which translates an interactive 3D-Model of the compound from X-ray chrystallography data. If you do not have this plug-in goto http://www.mdlchime.com/chime/ to download a free copy.

The Fujisawa laboratories in 1990 isolated FR-900848 from a fermentation broth of Streptoverticillium fervens. This compound shows potent, selective activity against filamentous fungi. The fatty acid side chain resembled highly a cholesteryl ester transfer protein inhibitor U-106305, isolated from Streptomyces sp. by Upjohn Laboratories. Both fatty acid side chains contained syn-trans-disubstituted quarter- and quinquecyclopropane systems. These systems appeared to take a helical conformation, but molecular models seemed to indicate that this conformation was quite flexible. Thus, their objective was to see how this helical structure might change in a macrocyclic formation. The synthesis of Coronanes 22 and 23 are reported here.

Total Synthesis of Coronane 22
Total Synthesis of Coronane 23