Hexamethylenetetramine-mediated transesterification of β-keto esters
…, ROMA de Souza, MLAA Vasconcellos, BL Oliveira…
文献索引:Ribeiro, Rodrigo S.; De Souza, Rodrigo O. M. A.; Vasconcellos, Mario L. A. A.; Oliveira, Bianca L.; Ferreira, Leonardo C.; Aguiar, Lucia C. S. Synthesis, 2007 , # 1 p. 61 - 64
As a model reaction, the transesterification of methyl acetoacetate (1a) with (-)-menthol (2a) was studied (Table [1] , entries 1-4: methods A, B, or C). The reaction between 1a (3 mmol) and (-)-menthol (2a; 1 mmol) in the presence of catalytic amounts of hexamethylenetetramine (0.3 mmol) in toluene solution at reflux (24 h) gave menthyl acetoacetate (3a) in 73% yield (method A, entry 1). When the transesterification was carried out in refluxing toluene with a Dean- ...