Selective Synthesis of Seven- and Eight-Membered Ring Sultams via Two Tandem Reaction Protocols from One Starting Material

Abstract

From one starting material, two tandem reaction protocols to synthesize seven- and eight-membered ring sultams were developed. One protocol employs intermolecular epoxide ring-opening by NaN₃, followed by an intramolecular 7-<i>endo-trig</i> oxa-Michael addition reaction. The second protocol applies to intermolecular aza-Michael addition of a primary amine, followed by 8-<i>endo-tet</i> intramolecular epoxide ring-opening of the resultant amine intermediate. Both protocols afforded the respective sultams in good yields under mild reaction conditions