1,2-Cyclohexenedicarboxylic acid

On the other hand, the reaction of the oxazolidone derivative of fumaric acid and butadiene was found to proceed in poor enantioselectivity as compared with the reaction carried out in the presence of excess amounts of the chiral titanium reagent, and the cyclohexenedicarboxylic acid derivative was obtained in 32-45% ee. In order to achieve wide applicability for the catalytic procedure, the reaction conditions were... 

This current-control feature can be illustrated in the electrochemical decarboxylation of vicinal diacids. These reagents have long been used as protecting groups for double bonds, since electrochemical deprotection by two-electron oxidation causes bis-decarboxylation and production of a C=C double bond [60]. In contrast, when platinized titanium dioxide is irradiated in the presence of one such vicinal diacid (cyclohexenedicarboxylic acid), the major reaction pathway leads to monodecarboxylation, rather than to benzene formation (Eq. 12). 

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