Synthesis of isoxazolobenzoxepanes via Michael addition of indoles to nitroalkenes and sequential intramolecular nitrile oxide cycloaddition

Nitroalkenes derived from O-propargyl salicylaldehyde undergo facile Michael addition with indoles leading to indole-derived Michael adducts. Intramolecular nitrile oxide cycloaddition (INOC) of the Michael adducts results in isoxazolobenzoxepanes in good to excellent yields.

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