Synthesis of Novel Cyclic Nitrones with gem‐Difluoroalkyl Side Chains Through Cascade Reactions

Abstract

New five‐membered cyclic nitrones with gem‐difluoroalkyl groups in γ‐position have been prepared by a 3‐step sequence starting from propargylic alcohols. This domino process involves a base‐mediated isomerization reaction to enones, which are trapped in situ by nitroalkane anions. In a final step, starting from these key precursors, a reduction‐cyclization process affords the target molecules. Mono‐ and bicyclic nitrones have been prepared by this route which allows, as well, the synthesis of nitrones with functional groups in terminal position of the side chain.