TMSOTf Mediated Aminocyclization/[1,3]‐Sulfonyl Migration on N‐Homopropargyl Hydroxylamines for the Stereoselective Synthesis of 3‐Sulfonyl Cyclic Nitrones

TMSOTf‐mediated 5‐endo‐dig aminocyclization followed by N‐ to C‐[1,3]‐sulfonyl migration on N¬‐homopropargyl hydroxylamines gave diastereoselective access to trisubstituted 3‐sulfonyl cyclic nitrone (3‐sulfonyl pyrroline N‐oxide) derivatives. The synthetic utility of the 3‐sulfonyl cyclic nitrone products was demonstrated through the diastereoselective synthesis of the sulfonyl‐substituted nonaromatic N‐heterocycles such as N‐hydroxy pyrrolidine, pyrrolidine‐fused isoxazoline, and isoxazolidine derivatives.