A one-pot two-step reaction (Knoevenagel condensation – reduction of the double bond) has been developed using calcium hydride as a reductant in the presence of a supported noble metal catalyst. The reaction between carbonyl compounds and active methylene compounds such as methylcyanoacetate, 1,3-dimethylbarbituric acid, dimedone and the more challenging dimethylmalonate, affords the corresponding
Electrochemical cyclization of tetramethyl esters of 2-substituted propane-1,1,3,3-tetracarboxylic acids in the presence of salts of hydrohalic acids
作者:M. N. Elinson、S. K. Fedukovich、G. I. Nikishin
DOI:10.1007/bf01184531
日期:1990.12
The chemical and electrochemical cyclization of tetramethyl esters of 2-substituted propane-1,1,3,3-tetracarboxylic acids in the presence of hydrohalic acid salt mediators were studied. It was found that the chemical variant of the cyclization of the corresponding alpha,alpha'-dianions of esters of propane-1,1,3,3-tetracarboxylic acids by the action of iodine or bromine is substantially inferior to the electrochemical variant. In the latter case, the esters of substituted cyclopropane-1,1,2,2-tetracarboxylic acids are formed in a 87-98% yield. The tetramethyl ester of 2-isopropylpropane-1,1,3,3-tetracarboxylic acid, which under the electrolysis conditions decomposes according to a Michael retroreaction is an exception.
Meerwein, Justus Liebigs Annalen der Chemie, 1908, vol. 360, p. 344
作者:Meerwein
DOI:——
日期:——
Ayoubi, Sahar Abdallah-El; Texier-Boullet, Francoise, Journal of Chemical Research - Part S, 1995, # 5, p. 208 - 209
Electrochemical cyclization of esters of propane-1,1,3,3-tetracarboxylic acids to give esters of substituted cyclopropane-1,1,2,2-tetracarboxylic acids