Advances in the Synthesis of Morpholin-3-ones and Morpholin-2-ones

This review covers advances in the synthesis of morpholin-3-ones and morpholin-2-ones. Besides the classical approaches for the preparation of both heterocycles that utilize intermolecular cyclizations of reactants or oxidation of morpholine and its derivatives, strategies employing various ring-expansion reactions using smaller heterocyclic substrates or multicomponent reactions are described. 1 Introduction 2 Synthesis of Morpholin-3-ones 2.1 By Formation of Two Bonds 2.2 By Formation of One Bond 2.3 By Introduction of Substituents 3 Synthesis of Morpholin-2-ones 3.1 By Formation of Two Bonds 3.2 By Formation of One Bond 3.3 By Introduction of Substituents 4 Conclusion