Synthesis of enantiopure 3-amino-1-azaspiro[4.5]decan-8-ones by halonium promoted cyclization of amino-tethered cyclohexenes

Haloaminocyclization reactions of polysubstituted γ-aminocyclohexenes give 3-amino-1-azaspiro[4.5]decan-8-one derivatives. The stereocontrol, chemoselectivity (N-attack vs O-attack), and influence of the halonium ion are discussed.