Metallic salt promoted radical cyclization of β-keto carboxamides and their corresponding β-enamino carboxamides

Article abstract of DOI:10.1021/jo000084u

Substituted lactams and spirolactams were obtained by Mn(III)-induced radical cyclization of unsaturated β-keto carboxamides. Treatment of the corresponding tertiary enamines under similar reaction conditions and in the presence of K₂CO₃ afforded the same cyclized products but with inversion of diastereoselectivity. The oxidation of optically pure secondary enamines leads to diastereomeric spirolactams in an approximately 3:1 ratio.