"As Simple as Possible, but Not Simpler"—The Case of Dehydroascorbic Acid

Kerber, Robert C.

doi:10.1021/ed085p1237

Cited by 36 publications

(29 citation statements)

References 22 publications

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“…8.0-9.0) [11] reacts with ascorbic acid (AscH 2 :p K a = 4.0) [12] to generate the phosphonium ascorbate [Ph 3 PCH 2 CO 2 R 1 ] + [AscH] À (4). [15] Avariety of monosubstituted alkenes 1 were subjected to the reaction with 2 (Table 1). Thecarbon radical species 5 undergoes electrophilic addition onto the carbon-carbon double bond of 1a to afford the secondary carbon radical 6,w hich then accepts ah ydrogen atom from pentafluorobenzenethiol to produce the ester 3a and at hiyl radical (ArSC).…”

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confidence: 99%

Synthesis of Elongated Esters from Alkenes

et al. 2018

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confidence: 99%

Synthesis of Elongated Esters from Alkenes

et al. 2018

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“…This paper is, in many ways, a companion piece to an earlier publication by Kerber on the correct structure of dehydroascorbic acid, the oxidized form of ascorbic acid (2). The Featured Molecules for this month (3) are drawn from these two papers.…”

Section: Jce Featured Molecules For October 2010mentioning

confidence: 99%

Structures of α-Oxocarboxylic Acids

Coleman

2010

J. Chem. Educ.

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In their paper on R-oxocarboxylic acids, Robert C. Kerber and Marian S. Fernando describe the role of the hydrated forms of those species in interpreting the corresponding acid dissociation constants (1). This paper is, in many ways, a companion piece to an earlier publication by Kerber on the correct structure of dehydroascorbic acid, the oxidized form of ascorbic acid (2). The Featured Molecules for this month (3) are drawn from these two papers. Table 1 lists the 3D, rotatable images in MOL format of the molecules available in the HTML version of this paper. They include one member of each enantiomeric pair of the oxidized ascorbic acid (molecule 1 in ref 1) and gas-phase and solution-phase structures of the species in Scheme 1 of ref 1 (with R = CH 3 ), pyruvic acid and its conjugate base and hydrated pyruvic acid and its conjugate base.A number of student exercises can be designed around these interesting molecules. The stereoisomers of dehydroascorbic acid provide useful practice with using R and S notation. Students might also follow the stereochemical course of the oxidation of ascorbic acid and see whether they can explain the origin of the stereochemistry that is observed for the product. Ascorbic acid is also included in the molecule collection for this month.A computational chemistry experiment could easily be devised around the equilibria in Scheme 1 of ref 1 for pyruvic acid (Figure 1). Using the provided structures as starting points, calculations at reasonably high levels of theory would allow students to explore the thermodynamics of this scheme in both the gas-phase and, more relevantly, in solution. The structures that are provided have been optimized at the MP2 level using the Dunning basis set cc-pVDZ. A collaborative project would enable individual students to carry out calculations, including frequencies, so as to provide thermodynamic data at several levels of theory and using several solvation models; students could then combine their data to explore the equilibrium system. The calculations done to produce the structures are consistent with the hydrated pyruvic acid being the dominant species in solution at low pH. These calculations could be extended further to include edited by Featured Molecule Description dehydroascorbic acid (in water; 1SRR) optimized at the DFT-B3LYP-6311þþG(d,p) level dehydroascorbic acid (in water; 1SRS) optimized at the DFT-B3LYP-6311þþG(d,p) level dehydroascorbic acid (in water; 1SSR) optimized at the DFT-B3LYP-6311þþG(d,p) level dehydroascorbic acid (in water; 1SSS) optimized at the DFT-B3LYP-6311þþG(d,p) level ascorbic acid optimized at the DFT-B3LYP-6311þþG(d,p) level hydrated pyruvic acid anion (in gas phase) optimized at the MP2 level using the Dunning basis set cc-pVDZ hydrated pyruvic acid anion (in water) optimized at the MP2 level using the Dunning basis set cc-pVDZ hydrated pyruvic acid (gas phase) optimized at the MP2 level using the Dunning basis set cc-pVDZ hydrated pyruvic acid (in water) optimized at the MP2 level using the Dunning basis set cc-pV...

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“…Vitamin C, aka ascorbic acid (AscH 2 ), is an extremely important natural redox cofactor, which exists extensively in vivo as an effective 1‐electron (including hydrogen atom) and/or 2‐electron (including hydride ion) donor to take part in a wide range of biochemical processes . For example, as a 1‐electron donor, ascorbate (AscH − ) can reduce dopamine‐ β ‐hydroxylase; as a hydrogen atom (or proton‐coupled electron) donor, AscH − can reduce α ‐tocopheroxyl radical, quinones, peroxynitrite, cytochrome b561, N ‐nitrosated tryptophan, glutathione peroxidase, etc . Just because ascorbic acid is a ubiquitous natural organic antioxidant and plays very important biochemical roles, the synthetic Vitamin C analog have drawn extensive examinations of many researchers for a long time .…”

Section: Introductionmentioning

confidence: 99%

“…[1,2] For example, as a 1-electron donor, ascorbate (AscH − ) can reduce dopamine-βhydroxylase; as a hydrogen atom (or proton-coupled electron) donor, AscH − can reduce α-tocopheroxyl radical, quinones, peroxynitrite, cytochrome b561, N-nitrosated tryptophan, glutathione peroxidase, etc. [3][4][5] Just because ascorbic acid is a ubiquitous natural organic antioxidant and plays very important biochemical roles, the synthetic Vitamin C analog have drawn extensive examinations of many researchers for a long time. [6][7][8] Examining the past publications on the chemistry of the synthetic vitamin C analog shows that although the structure, properties, and biofunctions of ascorbic acid as well as their relationships have received extensive examination [9][10][11] ; mechanism of the synthetic vitamin C analogs as bioorganic antioxidant has drawn little attention.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic, kinetic, and mechanistic examination of 1,5- dihydro-3,4-dihydroxy-2-pyrrolone derivatives as a new type of antioxidants to mimic vitamin C

Yuan

Shen

et al. 2016

J. Phys. Org. Chem.

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In this work, 1,5‐dihydro‐3,4‐dihydroxy‐2‐pyrrolone derivatives (XH2) and their anions (XH−) were designed and synthesized as the synthetic vitamin C analogs. The thermodynamic driving forces of the 8 possible elementary steps for XH2 to release 2 hydrogen atoms to become X in acetonitrile were determined using experimental methods. The mechanisms and the possible reaction intermediates of XH2 and XH− reacted by DPPH• in acetonitrile were examined or predicted using the determined thermodynamic analysis combining the kinetics.

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"As Simple as Possible, but Not Simpler"—The Case of Dehydroascorbic Acid

Cited by 36 publications

References 22 publications

Synthesis of Elongated Esters from Alkenes

Synthesis of Elongated Esters from Alkenes

Structures of α-Oxocarboxylic Acids

Thermodynamic, kinetic, and mechanistic examination of 1,5- dihydro-3,4-dihydroxy-2-pyrrolone derivatives as a new type of antioxidants to mimic vitamin C

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