The use of aqueous dimethylamine as reagent for the regiospecific C4-epimerization of cis-3-substituted 4-formyl-2-azetidinones
作者:Benito Alcaide、Moustafa F. Aly、Alberto Rodríguez-Vicente
DOI:10.1016/s0040-4039(98)01167-8
日期:1998.8
A simple and efficient method for the synthesis of trans-3-substituted 4-formyl-2-azetidinones 2 is described based on the regiospecific C4-epimerization of the cis-isomers 1 using aqueous dimethylamine as reagent in heterogeneous medium. (C) 1998 Elsevier Science Ltd. All rights reserved.
Palomo, Claudio; Cossio, Fernando P.; Cuevas, Carmen, Bulletin des Societes Chimiques Belges, 1992, vol. 101, # 7, p. 541 - 554
作者:Palomo, Claudio、Cossio, Fernando P.、Cuevas, Carmen、Ontoria, Jesus M.、Odriozola, Jose M.、Munt, Simon
DOI:——
日期:——
Base-Promoted Isomerization of <i>cis</i>-4-Formyl-2-azetidinones: Chemoselective <i>C</i>4-Epimerization vs Rearrangement to Cyclic Enaminones
作者:Benito Alcaide、Moustafa F. Aly、Carolina Rodríguez、Alberto Rodríguez-Vicente
DOI:10.1021/jo991984h
日期:2000.6.1
N-(p-methoxyphenyl)-beta-lactams can be used, and (ii) transformation is less compatible with heteroatomic substituents bonded to the C3 position of the 2-azetidinone ring. A highly general solution to these problems relies on the use of sodium carbonate as the isomerization reagent in different solvents. We also describe a novel base-promotedrearrangement of the beta-lactam ring to cyclic enaminones 6