Double Hetero-Michael Addition of N-substituted Hydroxylamines to Quinone Monoketals: Synthesis of Bridged Isoxazolidines

A general synthesis of bridged isoxazolidines from a double hetero-Michael addition of N-substituted hydroxylamines to quinone monoketals has been developed. The different addition order of N-benzylhydroxylamine and N-Boc hydroxylamine is also discussed. Moreover, the various functionalities in the isoxazolidine products allow facile derivatization.