Concise Asymmetric Synthesis of Fully Substituted Isoxazoline‐ N ‐Oxide through Lewis Base Catalyzed Nitroalkene Activation

Transforming isoxazoline‐ N ‐oxides : A concise asymmetric synthesis of isoxazoline‐ N ‐oxides is reported through secondary amine Lewis base catalyzed nitroalkene activation and sequential intermolecular condensation with aldehydes and ylides. Application of camphor‐derived chiral sulfur ylides gave the enantiomeric‐enriched isoxazoline‐ N ‐oxides in excellent yields and stereoselectivity. Simple transformations of isoxazoline‐ N ‐oxide led to the gram‐scale synthesis of a (−)‐clausenamide analogue in four steps, with excellent stereochemistry control (see scheme).