Synthesis of Cryptophycin 52 Using the Shi Epoxidation

A synthesis of cryptophycin 52 is reported using a Shi epoxidation strategy to install the epoxide moiety in a diastereoselective fashion. Several epoxidation results for cryptophycin substrates are disclosed followed by a discussion of the details relating to the preparation of cryptophycin 52 in two synthetic steps from one of the intermediate epoxides.