Methyl succinic acid

Further since XXV formed a quasi racemic compound with (+) methyl succinic acid XXVI, they have opposite configurations and so XXIV and XXVI have the same configuration. 

By polymerizing methylsorbate in the presence of catalysts obtained from optically active compounds containing (1R, 3R, 4S)-l-methyl-4-isopropyl-cyclohex-3-yl group, the methyl succinic acid formed by oxidation has the absolute structure (XV) thus in the polymer the tertiary carbon atoms bound to the methyl group have the absolute configuration (R) (XVI). The same steric correlation has been found in the case poly-styrylacrylic esters. 

Actually, levo rotatory methyl succinic acid and dextro rotatory methyl succinic acid were obtained by oxidation respectively from methyl sorbate and butyl sorbate polymers, obtained in the presence of (R)-2-methyl-butyl-lithium (36). 

In fact sorbic acid (XXXIII) has been transformed in menthyl-sorbate and the ester (XXXIV) has been polymerized (36) by butyl-lithium (Scheme 6) the prevalence of asymmetric carbon atoms having one of the possible configurations in the main chain of the polysorbic acid (XXXV), not isolated by the authors, has been proved by oxidizing the polymer and measuring the optical activity of the obtained methyl succinic acid, which actually was optically active and had an optical purity of 6% (36). 

AE55 c5h804 methyl succinic acid hoocch(ch3)ch2 DMSO PY E14NC104 0.1 - - 23.0 DME/SCE 035A. ... 

In a subsequent investigation by the author (1) 2-phosphono-3-(3,4-dimethoxyphenyl) methyl-succinic acid and other aromatic derivatives were prepared. 

Mono-methyl succinic acid is known also as pyro-tartaric acid as it is... 

Both of these di-methyl succinic acids are known. The symmetrical compound boils at 197° and the unsymmetrical at 139°. On further... 

Succinic acid Mono-methyl succinic acid Pyro-tartaric acid 1... 

This new acid, isomeric with mono-methyl succinic acid, pyro-tartaric acid, is known as glutaric acid, or systematically, as 1-5-pen-tan-di-oic acid. 

Ita-conic Acid.—There is, however, a third acid known of the same composition as the two preceding. It is called ita-conic acid and like the others is obtained from citric acid by distiUation. More than the two isomers just explained are not possible according to geometric isomerism. The isomerism, therefore, of this new acid with the other two must be explained in some other way and has been shown to be structural isomerism due to the different position of the double bond. We have spoken of the fact that both citra-conic and mesa-conic acids, by the addition of hydrogen, are converted into methyl succinic acid. This same result is obtained with ita-conic acid also as may be explained by the following reactions. 

While caoutchouc was first obtained by polymerizing isoprene it has been found that other hydrocarbons containing the buta i-ydi-ene group will likewise yield caoutchouc. Such hydrocarbons have been obtained from several sources, e.g., turpentiney petroleuniy coaly acetylene. Also compounds related to succinic acid, e.g., pyrotartaric acid (methyl succinic acid) are possible of transformation into isoprene. Levulinic acid, which is aceto propionic acid, CHa—CO—CH2—CH2—COOH, yields a cyclic sulphur compound, methyl-thiophen (p. 853), which, like methyl pyrrolidine, yields isoprene. Ethyl alcohol by conversion into acetone and then by aldol condensation with ethane yields 2-methyl buta 2-ene, CHa—C = CH—CHa which may be transformed... 

In 1960, Natta reported the first direct synthesis of an optically active polymer from an achiral monomer, where methyl sorbate was polymerized using (R)-2-pentyllithium [95]. Ozonolysis of the polymer (under conditions possibly allowing epimerization) produced (S)-methyl succinic acid in 5% ee, which provides evidence of asymmetric induction and absolute configuration of the polymer main chain. Since this initial report, a remarkable void in the Hterature exists concerning the synthesis of main-chain chiral polymers from achiral monomers using anionic initiators. Okamoto and Oishi have polymerized N-substituted maleimides with chiral anionic initiators (Scheme 14) [96,97]. The polymer is assumed to have predominantly a frans-diisotactic microstructuxe, which adopts a secondary helical structure. The absolute configuration of the main chain has... 

Formation of 14.6.4.1. Carbonylation of 14.6.5.5. H02C(CH2)3C02H (glutaric acid) Formation of 14.6.4.1. H02CCH2CH(CH3)C02H (methyl succinic acid)... 

The new 23-hydroxy-epimers of cholesterol have been prepared by boro-hydride reduction of the 23-ketone, and Grignard reactions on the cyanohydrin of pregnenolone acetate have been used to prepare both epimers of 20a,22-dihydroxycholesterol. Using optically pure half-esters of methyl succinic acid in Kolbe electrolytic coupling reactions with various bile acids the corresponding 25-d- and 25-L-cholestanoic acids have been prepared. ... 

In hydrogenations with H2 in D20 the product showed only CHD— stretches in the infrared. This observation excludes a fast H/D exchange on Pd, and implies a monohydridic mechanism of hydrogenation. With the same catalyst in an aqueous (D20) solution, itaconic acid is reduced under H2 to yield multiply deuterated methyl succinic acid having 1.97 deuterons at C3, 0.66 at C2 and none at Cl (Eq. 32) [83]. On the other hand, in an H20/ethyl acetate biphasic solvent mixture, the catalyst prepared in situ from [Rh(cod)Cl]2 and TPPTS catalyzed the reduction (with D2) of dimethyl itaconate with deuterium incorporation at C3 (2.06), C2 (0.78) and at Cl (0.18) [84], Similar results were obtained in toluene/methanol (1 1) with the Rh(I)-BPPM cationic catalyst [85], Again, these findings could be explained by a fast /3-elimination from the intermediate Rh(I)-alkyl. 

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