Total Synthesis of the CP-Molecules (CP-263,114 and CP-225,917, Phomoidrides B and A). 1. Racemic and Asymmetric Synthesis of Bicyclo[4.3.1] Key Building Blocks

A brief introduction into the chemistry of the CP-molecules is followed by first-generation synthetic sequences toward key building blocks for their total synthesis. Processes for both racemic and enantiomerically enriched bicyclo[4.3.1] ketone 6 or its equivalent are described, and the absolute stereochemistries of the optically enriched intermediates are determined. The efficient route developed to racemic 6 and the ready access to both enantiomers of key building blocks provided the opportunity for the total synthesis of the CP-molecules and determination of their absolute stereochemistry.