Total Synthesis of Batzelladine D

Stereoselective total synthesis of batzelladine D was accomplished in 15 steps. This synthesis features (i) successive 1,3-dipolar cycloaddition reactions to form the 2,5-disubstituted pyrrolidine ring system, (ii) esterification of the side chain to the bicyclic guanidine carboxylate, a common synthetic intermediate of batzelladine alkaloids, and (iii) tricyclic guanidine formation under the Mitsunobu reaction conditions.