title: Construction of 2-Pyrone Skeleton via Domino Sequence between 2-Acyl-1-Chlorocyclopropanecarboxylate and Amines.
abstract: A base-promoted domino reaction of 2-acyl-1-chlorocyclopropaneformic esters with amines is described. In the presence of inorganic bases like Cs2CO3 or Mg(OEt)2, the reaction proceeded smoothly in acetonitrile to afford 2-pyrone derivatives in modest to excellent yields (up to 97%). This reaction provides a straightforward and transition metal-free protocol to efficiently construct 2-pyrone skeleton. A possible mechanistic process involving 1,2-elimination of hydrogen chloride, aza-Michael addition, ring-opening, and intramolecular lactonization was suggested to rationalize the formation of the target 2-pyrone derivatives.
authors.affiliation: School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, People's Republic of China.
authors.forename: Yuequan
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, People's Republic of China.
authors.forename: Yuefa
authors.initials: Y
authors.lastname: Gong