1,2-Ethenedicarboxylic acid

Allomaleic acid allomalenic acid boletic acid butenedioic acid E297 1,2-ethenedicarboxylic acid lichenic acid trans-butenedioic acid NSC-2752 traMs-l,2-ethylenedicarboxylic acid U-1149 USAF EK-P-583. 

Ethene, chloro-, homopolymer. See Polyvinyl chloride trans-1,2-Ethenedicarboxylic acid. See Fumaric acid Ethene, 1,1-dichloro-. See Vinylidene chloride monomer Ethene, 1,2-dichloro-, (E)-. Seetrans-1,2-Dichloroethylene Ethene, 1,1-dichloro-, homopolymer. See Polyvinylidene chloride... 

Allomaleic acid 2-butenedioic acid trans-butenedioic acid boletic acid lichenic acid trans-l,2-ethenedicarboxylic acid... 

In an alkene such as ethene, the presence of the 7t-bond prevents rotation about the C=C bond. The hydrogen atoms on the separate carbons are either cis or trans to each other. When the alkene bears substituents on the separate carbon atoms, these are cis or trans to each other. Distinct geometric isomers are possible. These compounds have different properties. Thus c -ethenedicarboxylic acid is maleic acid (1.23). The carboxyl groups are close together in space and react together to form a cyclic anhydride (1.24). On the other hand, tranj-ethenedicarboxylic acid is fumaric acid (1.25) and no such interaction is possible. 

In the historical introduction to this volume (Sect. 1.1), it was mentioned that Buchner studied reactions of ethyl diazoacetate with ethenedicarboxylic acid in 1888. In the following year, he discovered pyrazole, obtained from methyl diazoacetate and dimethyl acetylenedicarboxylate followed by thermolysis. Finally, in 1893 Buchner et al. synthesized 4,5-dihydro-l//-pyrazole (2-pyrazoline) from methyl diazoacetate and methyl acrylate. Von Pechmann, the discoverer of diazomethane, performed analogous reactions of fumarates and maleates (von Pechmann, 1894, von Pechmann and Burkard, 1890). ... 

Z)-2-Butenedioic acid (Z)-l,2-ethenedicarboxylic acid malenic acid, maleinic acid, toxilic acid. 

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