Facile Synthesis of Azetidine Nitrones and Diastereoselective Conversion into Densely Substituted Azetidines

Discovery of an electrocyclization route to azetidine nitrones from N-alkenylnitrones has been shown to provide facile access to these unsaturated strained heterocycles. Reactivity studies have shown that these compounds undergo a variety of reduction, cycloaddition, and nucleophilic addition reactions to form highly-substituted azetidines with excellent diastereoselectivity. Taken together, these transformations provide a fundamentally different approach to azetidine synthesis than traditional cyclization by nucleophilic displacement and provide novel access to a variety of underexplored, strained heterocyclic compounds.