A meso specific reaction

Thottathil, John K.; Przybyla, Claire A.; Malley, Mary F.; Gougoutas, Jack Z.

doi:10.1016/s0040-4039(00)84305-1

Cited by 29 publications

(5 citation statements)

References 7 publications

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“…Due to the 3 J(C,H) coupling between the singlet at 6.15 ppm and C(8) of a furan ring, this hydrogen was evidenced as the proton H-C(6) of an amino acetal of furan-2carboxaldehyde. The 1 H and 13 C chemical shifts of C( 6) are well in line with those found for cyclic amino acetals formed from benzaldehyde and 5-(hydroxymethyl)pyrrolidine-2-one (Thottahil et al, 1986), thus confirming the proposed structure of 3a.…”

Section: Resultssupporting

confidence: 82%

Identification of Novel Colored Compounds Containing Pyrrole and Pyrrolinone Structures Formed by Maillard Reactions of Pentoses and Primary Amino Acids

Hofmann

1998

J. Agric. Food Chem.

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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-methylidene]-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-α-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. Keywords: Maillard reaction; colored compounds; (S)-4-hydroxy-5-methyl-2-[N-(1‘-carboxyethyl)pyrrolyl-2-methylidene]-2H-furan-3-one; (2R)-4-oxo-3,5-bis[(2-furyl)methylidene]tetrahydropyrrolo[1,2-c]-5(S)-(2-furyl)oxazolidine; (S)-4-[(E)-1-formyl-2-(2-furyl)ethenyl]-5-(2-furyl)-2-[(E)-(2-furyl)methylidene]-2,3-dihydo-α-amino-3-oxo-1H-pyrrole-1-acetic acid

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Section: Resultssupporting

confidence: 82%

Identification of Novel Colored Compounds Containing Pyrrole and Pyrrolinone Structures Formed by Maillard Reactions of Pentoses and Primary Amino Acids

Hofmann

1998

J. Agric. Food Chem.

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“…From these investigations, we think that these results, reproducible partially under exactly the same reaction conditions, don't reflect a reactivity difference of the L ‐ vs. DL ‐compounds as reported for pyroglutaminols . In contrary they outline difficulties in the crystallization of the ultimate compounds as well as the reversibility of the formation of both cyclic N,O ‐acetals 15 and acyclic N,N ‐aminals 11 under acid conditions .…”

Section: Resultssupporting

confidence: 49%

1,3,5‐Oxadiazine Framework by Oxygen vs. Nitrogen Trapping of an N‐Acyliminium Ion Derived from N,O‐bis‐TMS Pyroglutamic Acid

et al. 2017

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We report that the reaction of N,O-bis-TMS pyroglutamic acid with aldehydes, under basic or acid catalysis leads to O-bis-TMS adducts. Treatment of these N,O-acetals by TfOH affords azalactones or N,N'-substituted methylene-bis-pyroglutamic acids from the trapping of N-acyliminium species, respectively, with oxygen or nitrogen atom intramolecularly versus intermo-lecularly. Anodic oxidation of the amido acids, followed by diastereoselective oxa-cyclisation of new N-acyliminium salts, provides exclusively fused meso-1,3,5-oxadiazines with the stereochemistry secured by X-ray analysis. The reactivity of these skeletons under both alkaline and acid conditions was also envisioned and discussed.

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“…17 Our own work in this area has made use of the hemiaminal ethers ‡ 1a and 1b derived from pyroglutamic acid as a chiral template. 18,19 These compounds are of value since they can be readily prepared in enantiopure form; the hydroxyl and amide functionalities are simultaneously protected by a single benzylidene protecting group, making for economy in molecular mass; and the protecting group provides a bicyclic template which might be expected to exert good diastereocontrol. We 20-26 and others, 18,19,25,27-49 have demonstrated that the introduction of functionality α-, βand γto the lactam carbonyl of 1 is readily possible in a stereocontrolled sense.…”

Section: Introductionmentioning

confidence: 99%

Pyrrolidinones derived from (S)-pyroglutamic acid: penmacric acid and analogues

et al. 2003

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Alkylation reactions using alpha-halolactams or lactam enolates derived from bicyclic lactam templates can proceed with high endo- or exo- diastereoselectivity respectively. In the latter case, stereochemical correction by means of enolate generation and hindered phenol quench is possible with moderate efficiency. This protocol has been applied to the synthesis of protected penmacric acid and its analogues.

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A meso specific reaction

Cited by 29 publications

References 7 publications

Identification of Novel Colored Compounds Containing Pyrrole and Pyrrolinone Structures Formed by Maillard Reactions of Pentoses and Primary Amino Acids

Identification of Novel Colored Compounds Containing Pyrrole and Pyrrolinone Structures Formed by Maillard Reactions of Pentoses and Primary Amino Acids

1,3,5‐Oxadiazine Framework by Oxygen vs. Nitrogen Trapping of an N‐Acyliminium Ion Derived from N,O‐bis‐TMS Pyroglutamic Acid

Pyrrolidinones derived from (S)-pyroglutamic acid: penmacric acid and analogues

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