Azacycloalkanes: XXXIX. New Syntheses of 1H-Pyrrole-1-carboxylic acid and 1,2-dihydropyrrolo-[1,2-a]pyrazin-3(4H)-one derivatives
摘要:
New procedures have been developed for the synthesis of alpha-(2-formyl-1H-pyrrol-1-yl)-substituted carboxylic acids, alpha-(2-R-aminomethyl-1H-pyrrol-1-yl)-substituted carboxylic acids, and 1,2-dihydropyrrolo-[1,2-a]pyrazin-3(4H)-ones on the basis of furfurol and alpha-amino acids.
Identification of Novel Colored Compounds Containing Pyrrole and Pyrrolinone Structures Formed by Maillard Reactions of Pentoses and Primary Amino Acids
摘要:
Heating of pentoses with alanine in a ratio of 10:1 in aqueous solution at pH 7.0 generated the yellow 2-[(2-furyl)methylidene]-4-hydroxy-5-methyl-2H-furan-3-one (1), being well in line with data reported in the literature. Decreasing the relative concentrations of the pentose produced further colored nitrogen-containing compounds, among which (S)-4-hydroxy-5-methyl-2-[N-(1'-carboxyethyl)-pyrrolyl-2-methyldiene]-2H-furan-3-one (2) could be identified by spectroscopic and synthetic experiments. On the other hand, thermal treatment of an aqueous solution of pentose and L-alanine in the presence of furan-2-carboxaldehyde led to the formation of the novel red (2R)-4-oxo-3,5-bis-[(2-furyl)methylidene] tetrahydropyrrolo[1,2-c]-5(S)-(2-furyl)oxazolidine and its 5(R)-(2-furyl)oxazolidine diasteromer (3a/3b), which were characterized by several 1D- and 2D-NMR techniques, LC/MS, and UV-vis spectroscopy as well as by synthesis of the chromophoric substructure. In addition, the red compounds (S)-4-[(E)-1-formyl-2-(2-furyl)ethenyl]-5-(2-furyl)-2-[(E)-(2-furyl)methylidene]-2,3-dihydo-alpha-amino-3-oxo-1H-pyrrole-1-acetic acid (4b) and the corresponding 2-[(Z)-(2-furyl)-methylidene] isomer (4b) were identified in this Maillard mixture. Quantitative studies on the formation of these colorants clearly demonstrates the key role of 3-deoxypentos-2-ulose as an intermediate in the formation of 4a/4b. Reaction pathways leading to the colorants 2, 3a/3b, and 4a/4b from pentoses and alanine are discussed.
<scp>d</scp>-Galacturonic Acid: A Highly Reactive Compound in Nonenzymatic Browning. 2. Formation of Amino-Specific Degradation Products
作者:Steffen Wegener、Maria-Anna Bornik、Lothar W. Kroh
DOI:10.1021/acs.jafc.5b01121
日期:2015.7.22
as typical products of nonenzymatic uronic acid browning reactions. 2-(2-Formyl-1H-pyrrole-1-yl)propanoic acid (FPA) and 1-(1-carboxyethyl)-3-hydroxypyridin-1-ium (HPA) were identified as specific reaction products of uronic acids with amine participation like l-alanine. In contrast, the structurally related d-galacturonic acid methyl ester showed less browning activity and degradation under equal
Azacycloalkanes: XXXIX. New Syntheses of 1H-Pyrrole-1-carboxylic acid and 1,2-dihydropyrrolo-[1,2-a]pyrazin-3(4H)-one derivatives
作者:G. V. Mokrov、A. M. Likhosherstov、V. S. Troitskaya、T. A. Gudasheva
DOI:10.1134/s1070428009120136
日期:2009.12
New procedures have been developed for the synthesis of alpha-(2-formyl-1H-pyrrol-1-yl)-substituted carboxylic acids, alpha-(2-R-aminomethyl-1H-pyrrol-1-yl)-substituted carboxylic acids, and 1,2-dihydropyrrolo-[1,2-a]pyrazin-3(4H)-ones on the basis of furfurol and alpha-amino acids.