An Approach to the Core Structure of CP-225,917

The complex natural product CP-225, 917 (1), which is an inhibitor of Ras fanesyl tranferase,1～3] has at tracted much attention of several groups for its total synthesis. Our own approach is based on siloxy Cope rearrangement, which could be accomplished thermally in very good yield (99%) to from 10 to 11,4] a model compound lacking the side arms of the natural product. Its synthetic route from 6 is shown.