Synthesis of 2-epi-Pumiliotoxin C via a Challenging Intramolecular Hydroamination Key Step

The synthesis of 2-epi-pumiliotoxin C was achieved in ten steps from cyclohexadiene oxide, using a challenging Cope-type hydroamination key step. This cyclization was performed on a mixture of two epimeric hydroxylamines, and a boat transition state is proposed to explain the kinetic preference observed for the cyclization of the epimer leading to N-hydroxy-epipumiliotoxin C.