Diastereoselective synthesis of pyrrolidines using a nitrone/cyclopropane cycloaddition: Synthesis of the tetracyclic core of nakadomarin A

The synthesis of the tetracyclic core of nakadomarin A is described. The core contains all the heterocycles and the required stereocenters found in the natural product and provides a promising route to the target itself. The strategy utilizes a general, diastereoselective pyrrolidine synthesis that proceeds via a homo 3+2 dipolar cycloaddition. The scope of this methodology is also described.