A-Methyleneglutaric acid

Itaconic acid and its derivatives represent the only other alkene type which has so far been reduced with optical yields of over 90%. Using the usual cationic rhodium-diene (cod) precursor, a best optical yield of 94% was obtained with the diphosphine FPPM (59). The presence of triethylamine was necessary.267 With the related BPPM (Table 5), again in presence of triethyl-amine, optical yields up to 92% were achieved.268 [Rh(cod)(DIPAMP)]+ gave an optical yield of 88% for the dimethyl ester of itaconic acid, and 90% with a monoamide of a-methyleneglutaric acid.269... 

Hydroxynicotinic acid has been shown (Tsai et al., 1966) to be the first intermediate in the degradation of nicotinic acid by a Clostridium organism. In the presence of pyruvate other intermediates accumulated, of which two were identified 1,4,5,6-tetrahydro-6-oxonicotinic acid and a-methyleneglutaric acid. Infrared and NMR methods were used in defining the structures. 

The coenzyme model intermediate was synthesized by the reaction of vitamin Bi2s [Co(I)] with bis(tetrahydropyranyl) bromomethylitaconate. On standing in aqueous solution the model yields rearranged a-methyleneglutaric acid together with unrearranged methylitaconic acid and butadiene-2,3-dicarboxylic acid. 

P. Dowd, B. K. Trivedi, M. Shapiro, and L. K. Marwaha (1976), Vitamin Bj2 model studies. Migration of the acrylate fragment in the carbon-skeleton rearrangement leading to a-methyleneglutaric acid. J. Amer. Chem. Soc. 98, 7875-7877. 

Kung H-F, L Tsai, TC Stadtman (1971) Nicotinic acid metabolism. VIII. Tracer studies on the intermediary roles of a-methyleneglutarate, methylitaconate, dimethymaleate and pyruvate. J Biol Chem 246 6444-6451. 

Application of aza-annulation with cyclic enamino esters was reported in the synthesis of angiotensin converting enzyme inhibitor A58365A (323, Scheme 27).90 Aza-annulation of proline derivative 319, which was obtained in 4 steps from L-pyroglutamic acid, with a-methyleneglutaric anhydride (320) led to the formation of indolizidinone 321 as a mixture of diastereomers. Esterification followed by oxidation with DDQ gave 322, which was converted in 4 steps to the desired target 323. 

Free radicals are neutral species and therefore cannot normally be detected by ESI-MS. However, it is well known that radical reactions can be mediated by Lewis acids if the substrate acts as a Lewis base by chelating the metal atom of a Lewis acid in solution. Fiirmeier and coworkers studied tin hydride-mediated radical additions to dialkyl 2-alkyl-4-methyleneglutarates in the presence of Lewis acids (Scheme 5.5) [28,... 

Of AdoCbl-dependent reactions, the most important are (a) isomerizations leading to a rearrangement of the amino acid skeleton (of glutamate, a-methyleneglutarate, D-a-lysine, L-P-lysine, ornithine) and of methyl-malonyl-CoA, b) dehydration reactions, including dehydration of diols and glycerol, (c) deamination of aminoalcohols, and (d) reduction of ribonucleotide triphosphate to 2-deoxyribonucleotide triphosphate. Reactions a-c can be schematically represented as shown in Fig. 5.1. 

Common monomers for copoly(amide)s are adipic acid, TPA, hexa-methylenediamine (HMD) and e-caprolactam." 2-Methylpentamethylene-diamine and 2-ethyltetramethylenediamine are used for transparent PPA in combination with IPA. These diamines can be prepared by hydrogenation of the corresponding dinitriles. For example, 2-methylpentamethyl-enediamine can be prepared by hydrogenating 2-methyleneglutaric dinitrile, which is a dimerization product of acrylonitrile. 

Methyl-l,5-diaminopentane, 413 Methylene chloride, 17, 182, 265, 291 2-Methyleneglutaric dinitrile, 392 Methyl ethyl ketone, 260, 454 Methyl isobutyl ketone, 525 Methyl mercaptan, 240 Methyl methacrylate, 29, 254 a-Methylnadic anhydride, 452 4-(a-Methylnadimido)-benzoic acid, 452 2-Methyl-5-nitroaniline, 454 2-Methylpentamethylenediamine, 392, 393, 399, 409 A -Methyl-4-picolinium hexafluorophosphate, 157 Methylpiperidine, 399 4-Methyl-pyrazolo[3.4-b]quinoline, 37... 

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