Résumé
A stereoselective one‐pot double derivatization of cyclobutene‐1‐carboxylic acid via a mild organic base catalyzed amidation/aza‐Michael addition of benzo[d]oxazol‐2(3H)‐ones has been developed. This unprecedented tandem reaction provides access to novel β‐ N ‐heterocyclic cyclobutane carboximide derivatives with a trans geometry. The carboximide moiety reacts smoothly with nucleophiles, allowing access to diverse derivatives of trans ‐β‐ N ‐heterocyclic cyclobutanecarboxylic acid, including peptidomimetic structures.