2- alkanoic acid carbon dioxide

These topics are discussed in more detail in other chapters of this text. Formally, the pyrolytic elimination of sulphur dioxide from a sulphone, with the concomitant formation of a new carbon-carbon bond, constitutes a reduction at sulphur. These reductions have been valuable in the formation of new molecules, especially macrocycles and cyclophanes, and have been reviewed by Vdgtle and Rossa . Pyrolytic elimination of sulphur dioxide has been used by Julia and coworkers in the formation of mixtures of isoprenoids , and by Takayama and collaborators in the stereoselective synthesis of vitamin Dj 19-alkanoic acids . ... 

Elimination of carbon dioxide from carboxyl, water from alcoholic hydroxyl, carboxylic acid from alkanoate, and hydrogen chloride from chlorine side groups or chain ends are typical thermal decomposition reactions in the temperature range 250-350°C. Hydrogen chloride is an important product of poly(vinyl chloride) because every second carbon atom of the hydrocarbon polymer chain is chlorine substituted. But hydroxyl, alkanoate and free carboxylic acid groups normally occur only at the ends of the macromolecular chains in customary plastics, thus the contribution of their elimination to the volatile pyrolysis products is negligible. 

Under high-pressure conditions, volatile species, such as hydrogen, carbon dioxide, and in some cases olefins or alkanes, are accumulated on the anode surface, which may affect the product distribution [33,36]. An aqueous Kolbe electrolysis of an alkanoic acid (in the range C4-C6) tends to give higher yields of the Kolbe dimers when run at elevated pressure (100 kPa) than an equivalent experiment at atmospheric pressure. 

Photo-oxidative decarboxylation of indole-3-acetic acid in the presence of pyrimido[5,4-g]pteridine W-oxide has been described. Photoelimination of carbon dioxide has been observed in a variety of esters including aromatic esters, substituted l-naphthylmethyl alkanoates and ethyl a-oxocarboxylates,and is one pathway described in a review of the photochemistry of 2(3H)- and 2(5H) furanones.Ethylene, ethanol and carbon dioxide are the only... 

In 1849, Kolbe found that electrolysis of potassium acetate generated carbon dioxide (CO2) and ethane, presumably via an acetoxy radical (107). The methyl radical ( CH3) generated from potassium acetate coupled to give ethane. The reaction works very well with long, straight chain alkanoic acids. This reaction is... 

Oxalic and malonic acids, as well as a-hydroxy acids, easily react with cerium(IV) salts (Sheldon and Kochi, 1968). Simple alkanoic acids are much more resistant to attack by cerium(IV) salts. However, silver(I) salts catalyze the thermal decarboxylation of alkanoic acids by ammonium hexanitratocerate(IV) (Nagori et al., 1981). Cerium(IV) carboxylates can be decomposed by either a thermal or a photochemical reaction (Sheldon and Kochi, 1968). Alkyl radicals are released by the decarboxylation reaction, which yields alkanes, alkenes, esters and carbon dioxide. The oxidation of substituted benzilic acids by cerium(IV) salts affords the corresponding benzilic acids in quantitative yield (scheme 19) (Hanna and Sarac, 1977). Trahanovsky and coworkers reported that phenylacetic acid is decarboxylated by reaction with ammonium hexanitratocerate(IV) in aqueous acetonitrile containing nitric acid (Trahanovsky et al., 1974). The reaction products are benzyl alcohol, benzaldehyde, benzyl nitrate and carbon dioxide. The reaction is also applicable to substituted phenylacetic acids. The decarboxylation is a one-electron process and radicals are formed as intermediates. The rate-determining step is the decomposition of the phenylacetic acid/cerium(IV) complex into a benzyl radical and carbon dioxide. 

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