Dicarboxylic acids with acetylenic bonds

Witten et al. (1973) identified adipic and 3-methyladipic acids and also reported the presence in urine, using GC-MS, of aconitic and isocitric acids in addition to citrate. Mamer et al, (1971) reported the occurrence of several hydroxyaliphatic acids in addition to those already identified by other workers, and Mamer and Tjoa have identified 2-ethylhydracrylic acid in urine derived from isoleucine metabolism (Mamer and Tjoa, 1974). Urine from healthy children and adults may contain low amounts of aliphatic dicarboxylic acids of chain length C4-C8 (Lawson et ai, 1976). Pettersen and Stokke (1973) reported a series of 3-methyl-branched C4-C8 dicarboxylic acids in urine from normal subjects, and Lindstedt and co-workers have identified other dicarboxylic acids with cyclopropane rings and acetylenic bonds as well as a series of cis and trans mono-unsaturated aliphatic dicarboxylic acids (Lindstedt et al., 1974,1976 Lindstedt and Steen, 1975). 

The development of unsaturated polyanhydrides responded to the necessity of improving the mechanical properties of the polymers in applications such as the temporary replacement of bone. " Unsaturated polyanhydrides, prepared by melt or solution polymerization, include homopolymers of fumaric acid (FA), acetylene-dicarboxylic acid (ACDA), and 4,4 -stilbenzenedi-carboxylic acid (STDA). The chemical structures of poly(FA) and poly(ACDA) are shown in Table 1. These polymers are highly crystalline and insoluble in common organic solvents. The double bonds of these monomers make them suitable for further crosslinking to improve mechanical properties of polyanhydrides. When copolymerized with aliphatic diacids, less crystalline polymers with enhanced solubility in chlorinated solvents result. 

As described by H. W. Sternberg [440], hydrocarboxylation of acetylenes is possible also in alkaline medium, where (Ni3(CO)8) is believed to function as the CO-donor. Thus, Sternberg obtained 25 % of trans-a-phenyl cinnamic acid besides 67 % of tetraphenyl butadiene, starting from diphenyl acetylene. Starting with octynes J. M. J. Tetteroo reported a considerably lower yield [146]. As mentioned on page 83, different reaction products are obtained with Co- or Fe-carbonyls on the one hand and Ni(CO)4 on the other hand. Contrary to nickelcarbonyl, cobaltcarbonyls are of such activity that the initially formed unsaturated acids are hydrocarboxylated a second time at the double bond. Thus, dicarboxylic acids or their derivatives are obtained by hydrocarboxylation of acetylenes with cobaltcarbonyls as catalysts [226, 388-391, 393-397, 441] (see also table 39). 

The glycol 2-butyne-l,4-diol and acetylene dicarboxylic acid have been reacted with MA and various glycols to prepare polyesters containing the acetylenic bond/ " The soluble copolymers could be readily crosslinked. 

The use of carbon dioxide in the synthesis of functional molecules is of considerable interest. An example is the industrially important reaction of epoxides with carbon dioxide to give cyclic carbonates. Also, functionalization of acetylenes and dienes with carbon dioxide on transition metal catalysts gives rise to the formation of cyclic lactones or dicarboxylic acids. The activation of carbon dioxide by metal complexes was reviewed in 1983 . Reactions of carbon dioxide with carbon-carbon bond formation catalyzed by transition metal complexes was reviewed in 1988 ", heterogenous catalytic reactions of carbon dioxide were reviewed in 1995, and the use of carbon dioxide as comonomers for functional polymers was reviewed in 2005. ... 

Af-Unsubstituted pyrazoles and indazoles add to compounds containing activated double and triple bonds (67HC 22)1,B-76MI40402>. Amongst C—C double and triple bonds, maleic anhydride, acrylic acid esters and nitriles, acetylene-carboxylic and -dicarboxylic esters (78AHC(23)263), quinones, and some a,/3-unsaturated ketones have been used with success. Phenylacetylene reacts with pyrazole in the presence of Na/HMPT as catalyst to yield the Z isomer of 1-styrylpyrazole in a highly stereoselective reaction (78JHC1543). 

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