Recent Developments in the Synthesis of Fused Sultams

Some of the recent developments in the synthesis of fused sultams are discussed. A cascade ring-closure metathesis/isomerization and subsequent radical cyclization was utilized to generate tricyclic sultams from bisallylsulfonamides by Piva and co-workers. de Meijere and co-workers developed a facile synthesis of tricyclic sultams by cycloisomerization of 4,9-diheterododecadienyne followed by intramolecular [4 + 2]-cycloaddition. A synthesis of condensed sultams deriving from intramolecular 1,3-dipolar cycloadditions of nitrones was described by Yamamoto and co-workers. Landry and co-workers reported the synthesis of the tetracyclic N-8-quinolinyl benzenesultam, a novel nuclear factor kappa B (NF-kB) inhibitor. In 2004, Ley and co-workers developed the total synthesis of the cytotoxic antitumor natural product epothilone C by coupling of the three fragments.