The crystal structure of L-ascorbic acid, `vitamin C'. I. The X-ray analysis

Hvoslef, J.

doi:10.1107/s0567740868001664

Cited by 121 publications

(49 citation statements)

References 6 publications

(8 reference statements)

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“…The use of each of these intermediates (2)(3)(4)(5) will be illustrated in the following discussion of the different syntheses of L-ascorbic acid.…”

mentioning

confidence: 99%

Synthesis of L-Ascorbic Acid

Crawford

1982

Ascorbic Acid: Chemistry, Metabolism, and Uses

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The methods by which L-ascorbic acid has been synthesized are readily divided into three major categories. The first involves coupling a C 1 fragment and a C 5 fragment, and the second involves coupling a C 2 fragment and a C 4 fragment. The third involves the conversion of a C 6 chain into the correct oxidation state and stereochemical configuration. All of these approaches will be reviewed with special regard given to those syntheses that are suitable for the prepara tion of analogues of L-ascorbic acid, the preparation of radiolabeled derivatives of L-ascorbic acid, and the current commercial synthesis of L-ascorbic acid.Following the isolation of crystalline "hexuronic acid" from the adrenal cortex of the ox and from orange juice in 1928 (1) and the determina tion in 1933 (2) that the structure of this material was 1 (with other proton tautomers shown in Scheme 1), efforts were begun to synthesize this novel vitamin. In a very short time several syntheses were success fully accomplished that confirmed that the structure of L-ascorbic acid or vitamin C was indeed that proposed (2). Complete details of the crystal structure of 1 have since been obtained by both x-ray (3,4) and neutron diffraction (5) analysis and are approximated by structure 1a.Efforts directed toward the synthesis of L-ascorbic acid have been governed by the following factors:1. The need to synthesize material to confirm the structure and provide larger quantities of material for further study. 2. The desire to synthesize analogues of L-ascorbic acid. 3. The desire to prepare radiolabeled material for use in the study of L-ascorbic acid metabolism in plants, fish, animals, and humans. 4. The need to develop a commercially viable, low cost syn thesis. This is illustrated by the fact that in 1934 1 kg of L-ascorbic acid sold for $7000 (6).

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“…The use of each of these intermediates (2)(3)(4)(5) will be illustrated in the following discussion of the different syntheses of L-ascorbic acid.…”

mentioning

confidence: 99%

Synthesis of L-Ascorbic Acid

Crawford

1982

Ascorbic Acid: Chemistry, Metabolism, and Uses

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“…The influence of temperature on the chemical stability of L-ascorbic acid has mainly been studied in solution and thermal decomposition has rarely been studied in the solid state; only calorimetric and gravimetric data are available in the literature [4,5]. In addition, although the crystal structure of vitamin C is known for years [6], both from single-crystal X-ray and neutron diffraction measurements at and below room temperature [6][7][8][9][10][11][12][13], the influence of heating on crystalline Lascorbic acid has never been studied by X-ray diffraction.…”

Section: Introductionmentioning

confidence: 99%

“…The references of the most useful CSD files have been compiled in Table 1 together with a few other publications on the structure [6][7][8][9][10][11]. L-ascorbic acid crystallizes in the monoclinic system with the non-centrosymmetric space group P2 1 , with 4 molecules per unit-cell (Z = 4).…”

Section: Introductionmentioning

confidence: 99%

Thermal expansion of L-ascorbic acid

Nicolaı̈

Tamarit

Céolin

et al. 2017

Eur. Phys. J. Spec. Top.

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The specific volume of vitamin C has been investigated by X-ray powder diffraction as a function of temperature from 110 K up to complete degradation around 440K. Its thermal expansion is relatively small in comparison with other organic compounds with an expansivity  v of 1.2(3) ×10 -4 K -1 . The structure consists of strongly bound molecules in the ac plane through a dense network of hydrogen bonds. The thermal expansion is anisotropic. Along the b axis, the expansion has most leeway and is about 10 times larger than in the other directions.2

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“…An almost identical simulation was obtained after geometry optimization of the hydrogen positions using the ambient temperature X-ray structure (lascac10) [35] as a starting point, which is expected…”

Section: H Shift Parametersmentioning

confidence: 73%

“…[34] These include X-ray structures obtained at both ambient temperature (lascac10) [35] and at low temperatures: 120 K (lascac12) [36], 100 K (lascac14) and 90 K (lascac15) as well as a neutron diffraction refinement (lascac01) [37] of the hydrogen atom positions in the ambient temperature structure. In all cases the space group is P21, and there are four L-ascorbic acid molecules in the unit cell and two in the asymmetric unit, related to one another by a pseudo symmetry operation.…”

Section: Ascorbic Acid Crystal Structuresmentioning

confidence: 99%

1 H CSA parameters by ultrafast MAS NMR: Measurement and applications to structure refinement

Miah

Cresswell

Iuga

et al. 2017

Solid State Nuclear Magnetic Resonance

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A 1 H anisotropic-isotropic chemical shift correlation experiment which employs symmetry-based recoupling sequences to reintroduce the chemical shift anisotropy in ν1 and ultrafast MAS to resolve 1 H sites in ν2 is described. This experiment is used to measure 1 H shift parameters for L-ascorbic acid, a compound with a relatively complex hydrogen-bonding network in the solid. The 1 H CSAs of hydrogen-bonded sites with resolved isotropic shifts can be extracted directly from the recoupled lineshapes. In combination with DFT calculations, hydrogen positions in crystal structures obtained from X-ray and neutron diffraction are refined by comparison with simulations of the full two-dimensional NMR spectrum. The improved resolution afforded by the second dimension allows even unresolved hydrogen-bonded sites 1 H to be assigned and their shift parameters to be obtained.

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The crystal structure of L-ascorbic acid, `vitamin C'. I. The X-ray analysis

Cited by 121 publications

References 6 publications

Synthesis of L-Ascorbic Acid

Synthesis of L-Ascorbic Acid

Thermal expansion of L-ascorbic acid

1 H CSA parameters by ultrafast MAS NMR: Measurement and applications to structure refinement

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