Synthesis of Cyclic Vicinal Trifluoromethylated Hydroxylamine and Nitrone Based on Perfluorodiacetyl

Perfluorodiacetyl (PFDA) demonstrates high‐synthetic potential in reaction with bifunctional nucleophilic reagents. Therefore, PFDA is a useful reagent in the synthesis of CF 3 ‐substituted heterocycles. In this work, we explored the reaction of PFDA with a sterically hindered bis‐hydroxylamine, isolated the products and clarified their structures. It was found that the reaction initially gave the 5,5,6,6‐tetramethyl‐2,3‐bis(trifluoromethyl)pyperazine‐1,2,3,4‐tetraol heterocycle with a unique set of functional groups. This tetraol was shown to easily undergo dehydration with formation of the first cyclic α‐CF 3 ‐substituted nitrone.