Total Synthesis of the CP Molecules CP-225,917 and CP-263,114— Part 2: Evolution of the Final Strategy

A synthetic labyrinth endowed with countless obstacles, yet filled with numerous hidden treasures, had to be overcome to reach the CP molecules CP-263,114 (1) and CP-225,917 (2). Their complex molecular frameworks coupled with the array of sensitive functionalities present amount to a formidable synthetic challenge. Moreover, these compounds possess interesting biological properties. Although the first synthetic strategies ended before the goals were achieved, in spite of careful preparation and numerous model studies, enough information was gathered en route to enable a revised approach to be formulated, which finally culminated in success.