The Aza‐Prins Reaction in the Synthesis of Natural Products and Analogues

The classical Prins cyclization reaction has been one of the most studied reactions during the last two decades and it has found many applications in key steps of natural product syntheses, especially for products containing pyran units and related structures in their core skeletons. The nitrogen‐based version of the Prins reaction, aza‐Prins cyclization, has found its own relevance in organic synthesis owing to the fact that it gives direct access to piperidines, which are even more widespread in natural products and in drugs. Even though the potential scope of the reaction is vast, and despite it having afforded significant progress in the synthesis of various azaheterocycles, its applications in the field of natural product synthesis is massively underdeveloped in comparison with the classical Prins reaction. A compilation of the applications of aza‐Prins cyclization in the preparation of natural products and selected analogues, especially compounds of potential biological interest, is presented, with emphasis placed on the key roles of this reaction in the total synthesis of these products.