N-O tethered carbenoid cyclopropanation facilitates the synthesis of a functionalized cyclopropyl-fused pyrrolidine.

We report a facile approach to a cyclopropyl-fused pyrrolidine, which contains four stereogenic centers, by employing the N-O tethered carbenoid methodology. The synthesis was facilitated by the development of a direct Mitsunobu reaction of alcohols with N-alkyl-N-hydroxyl amides to give diazo precursors, which upon intramolecular cyclopropanation yielded a library of N-O containing cyclopropyl-fused bicyclic intermediates. Elaboration of the N-O moiety of one member of this library resulted in the formation of the desired pyrrolidine ring demonstrating the potential of this methodology for making cyclopropyl-fused heterocycles.