Competitive Formation of β-Enaminones and 3-Amino-2(5H)-furanones from the Isoxazolidine System: A Combined Synthetic and Quantum Chemical Study
作者:Daniela Iannazzo、Elisa Brunaccini、Salvatore V. Giofrè、Anna Piperno、Giovanni Romeo、Simone Ronsisvalle、Maria A. Chiacchio、Giuseppe Lanza、Ugo Chiacchio
DOI:10.1002/ejoc.201000579
日期:2010.10
3-alkoxycarbonyl-4-acyl- or 3,4-dialkoxycarbonyl-substituted isoxazolidines with a mild base, such as tetrabutylammonium fluoride, affords β-enaminones and/or 3-methylamino-2(5H)-furanones according to the nature of the substituents at C 4 and C 5 . Two alternative mechanisms (lactonization and retro-aldolization) have been rationalized by DFT quantumchemical methods. Any realistic theoretical modeling requires