Preparation and photolysis of diaryl esters of acetylenedicarboxylic acid
作者:Marcedes Alvaro、Hermenegildo García、Miguel A. Miranda、Jaime Primo
DOI:10.1016/0040-4020(92)85017-9
日期:1992.1
of acetylenedicarboxylic acid with the corresponding phenols catalyzed by sulfuric or -toluenesulfonic acids and also through acetylenedicarbonyl chloride. The accompanying by-products have been characterized. Attempted esterification using N,N′-dicyclohexylcarbodiimide as condensing agent gives an asymmetric ester amide and a substituted uracil . Photolysis of the aryl esters in benzene solution affords
A new and efficient route to 4-carboxymethylcoumarins mediated by vinyltriphenylphosphonium salt
作者:Issa Yavari、Rahim Hekmat-Shoar、Afsaneh Zonouzi
DOI:10.1016/s0040-4039(98)00206-8
日期:1998.4
Protonation of the reactive 1:1 intermediate produced in the reaction between triphenylphosphine and dimethyl acetylenedicarboxylate by substituted phenols leads to a vinyltriphenylphosphonium salt, which undergoes aromatic electrophilic substitution reaction with the phenolate conjugate base to produce 4-carboxymethylcoumarins in fairly high yields. (C) 1998 Elsevier Science Ltd. All rights reserved.
Biginelli, Gazzetta Chimica Italiana, 1894, vol. 24 II, p. 492