3-O-Ethyl-l-ascorbic acid

Jin, S.; Miao, X.

doi:10.1107/S1600536808009963

organic compounds

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Volume 64| Part 5| May 2008| Page o860

doi:10.1107/S1600536808009963

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3-O-Ethyl-L-ascorbic acid

Shu Jin ^a ^* and Xiaoqin Miao ^a

^aNanjing Research Institute for Comprehensive Utilization of Wild Plants, Jiangwangmiaojie 4#, Nanjing 210042, People's Republic of China
^*Correspondence e-mail: sjinlab@msn.com

(Received 27 March 2008; accepted 11 April 2008; online 16 April 2008)

In the crystal structure of the title compound, C₈H₁₂O₆, molecules are linked to each other by O—H⋯O hydrogen bonding.

Related literature

For general background, see: Nihro et al. (1992 ); Satoh et al. (1994 ).

Experimental

Crystal data

C₈H₁₂O₆
M_r = 204.18
Orthorhombic, P 2₁ 2₁ 2₁
a = 4.6690 (9) Å
b = 11.939 (2) Å
c = 16.794 (3) Å
V = 936.2 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.13 mm⁻¹
T = 293 (2) K
0.20 × 0.20 × 0.10 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: none
1973 measured reflections
1024 independent reflections
882 reflections with I > 2σ(I)
R_int = 0.028
3 standard reflections every 200 reflections intensity decay: none

Refinement

R[F² > 2σ(F²)] = 0.040
wR(F²) = 0.138
S = 1.00
1024 reflections
137 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2A⋯O5ⁱ	0.83 (3)	2.06 (3)	2.873 (3)	168 (5)
O5—H5A⋯O3ⁱⁱ	0.91 (5)	1.90 (4)	2.748 (4)	154 (4)
O6—H6A⋯O6ⁱⁱⁱ	0.87 (5)	1.87 (5)	2.715 (4)	163 (4)
Symmetry codes: (i) $[-x, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (ii) $[-x, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (iii) $[x-{\script{1\over 2}}, -y+{\script{3\over 2}}, -z+1]$ .

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 ); program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808009963/xu2411sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808009963/xu2411Isup2.hkl

checkCIF report

Comment top

L-Ascorbic acid has been widely employed as an antioxidant for stabilization of nutrients. However, the low lipophilicity of it and its susceptibility to thermal and oxidative degradation restricts its field of application and has raised considerable interest in the study of ascorbic acid derivatives with increased lipophilicity and stability. The title compound is one of the lipophilic ascorbic acid derivatives, which exhibit antioxidative properties (Nihro et al.,1992) and can be used as antioxidant in food (Satoh et al., 1994). As part of our ongoing study on ascorbic acid derivatives, we report here the crystal structure of the title compound (Fig. 1).

The geometrical parameters of the compound are normal. The C3—C4 bond distance of 1.332 (5) Å and O3—C5 bond distance of 1.215 (4) Å indicate typical C═C and O═C double bonds. Molecules are linked to each other by O—H···O hydrogen bonding (Table 1).

Related literature top

For general background, see: Nihro et al. (1992); Satoh et al. (1994).

Experimental top

0.1 mol 5,6-O,O-Isopropylidene L-ascorbic acid was dissolved in 100 ml DMSO at room temperature, and 0.12 mol NaHCO₃ was added with stirring. After the addition of 0.1 mol ethyl bromide, the mixture was stirred at 313 K for 6 h. The solvent was distilled of at 333 K under reduced pressure. The residue was dissolved in 50 ml water and extracted five times with ethyl acetate (100 ml/time). The collected organic phase was dried over Na₂SO₄ and the solvent was evaporated at reduced pressure. 100 ml 0.1 M HCl was added to the residue, refluxed for 15 min and then the solvent was evaporated at reduced pressure. The residue was dissolved in ethyl acetate; single crystals were obtained by slow evaporation of the ethyl acetate solution.

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

Fig. 1. The molecular structure of (I), with atom labels and 30% probability displacement ellipsoids for non-H atoms.

3-O-Ethyl-L-ascorbic acid top

Crystal data top

C₈H₁₂O₆	D_x = 1.449 Mg m⁻³
M_r = 204.18	Melting point: 385 K
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 25 reflections
a = 4.6690 (9) Å	θ = 10–13°
b = 11.939 (2) Å	µ = 0.13 mm⁻¹
c = 16.794 (3) Å	T = 293 K
V = 936.2 (3) Å³	Plate, colourless
Z = 4	0.20 × 0.20 × 0.10 mm
F(000) = 432

Data collection top

Enraf–Nonius CAD-4 diffractometer	R_int = 0.028
Radiation source: fine-focus sealed tube	θ_max = 25.2°, θ_min = 2.1°
Graphite monochromator	h = 0→5
ω/2θ scans	k = 0→14
1973 measured reflections	l = −20→20
1024 independent reflections	3 standard reflections every 200 reflections
882 reflections with I > 2σ(I)	intensity decay: none

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.040	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.138	w = 1/[σ²(F_o²) + (0.1P)² + 1.3P] where P = (F_o² + 2F_c²)/3
S = 1.00	(Δ/σ)_max < 0.001
1024 reflections	Δρ_max = 0.18 e Å⁻³
137 parameters	Δρ_min = −0.26 e Å⁻³
1 restraint	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.121 (14)

Crystal data top

C₈H₁₂O₆	V = 936.2 (3) Å³
M_r = 204.18	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 4.6690 (9) Å	µ = 0.13 mm⁻¹
b = 11.939 (2) Å	T = 293 K
c = 16.794 (3) Å	0.20 × 0.20 × 0.10 mm

Data collection top

Enraf–Nonius CAD-4 diffractometer	R_int = 0.028
1973 measured reflections	3 standard reflections every 200 reflections
1024 independent reflections	intensity decay: none
882 reflections with I > 2σ(I)

Refinement top

R[F² > 2σ(F²)] = 0.040	1 restraint
wR(F²) = 0.138	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	Δρ_max = 0.18 e Å⁻³
1024 reflections	Δρ_min = −0.26 e Å⁻³
137 parameters

Special details top

Experimental. ¹H NMR (500 MHz, CDCl3): δ1.39 (3H, t), 3.86 (2H, m), 3.96 (1H, m), 4.54 (2H, q), 4.71 (1H, d) p.p.m.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.5474 (6)	0.5579 (2)	0.82156 (13)	0.0513 (7)
C1	0.6281 (17)	0.6421 (5)	0.9472 (3)	0.0896 (18)
H1A	0.5996	0.6352	1.0036	0.134*
H1B	0.5371	0.7093	0.9285	0.134*
H1C	0.8295	0.6455	0.9359	0.134*
O2	0.1035 (7)	0.3667 (2)	0.85756 (15)	0.0563 (8)
H2A	0.027 (12)	0.305 (2)	0.851 (3)	0.084*
C2	0.5046 (14)	0.5463 (4)	0.90741 (19)	0.0664 (14)
H2B	0.3016	0.5418	0.9192	0.080*
H2C	0.5953	0.4782	0.9262	0.080*
C3	0.4076 (7)	0.4855 (2)	0.77537 (18)	0.0385 (8)
O3	−0.0350 (7)	0.2854 (2)	0.69573 (15)	0.0555 (7)
C4	0.2202 (8)	0.4033 (3)	0.78834 (19)	0.0401 (8)
O4	0.2730 (6)	0.41543 (19)	0.65249 (13)	0.0451 (7)
C5	0.1347 (8)	0.3595 (3)	0.7110 (2)	0.0419 (8)
O5	0.0863 (5)	0.64292 (19)	0.67658 (15)	0.0419 (6)
H5A	0.088 (11)	0.671 (3)	0.727 (3)	0.063*
O6	0.3693 (6)	0.7318 (2)	0.53918 (14)	0.0466 (7)
H6A	0.213 (11)	0.729 (4)	0.511 (3)	0.070*
C6	0.4518 (7)	0.4996 (2)	0.68745 (17)	0.0355 (8)
H6B	0.6523	0.4838	0.6744	0.043*
C7	0.3734 (7)	0.6151 (3)	0.65672 (17)	0.0329 (7)
H7A	0.5026	0.6705	0.6804	0.039*
C8	0.4004 (9)	0.6198 (3)	0.56722 (18)	0.0427 (9)
H8A	0.5861	0.5910	0.5514	0.051*
H8B	0.2544	0.5729	0.5432	0.051*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0599 (17)	0.0583 (14)	0.0356 (11)	−0.0134 (14)	−0.0067 (13)	0.0078 (11)
C1	0.122 (5)	0.091 (3)	0.056 (3)	−0.020 (4)	0.007 (3)	−0.013 (2)
O2	0.0731 (19)	0.0566 (14)	0.0391 (12)	−0.0154 (17)	0.0083 (14)	0.0088 (12)
C2	0.096 (4)	0.068 (2)	0.0350 (16)	−0.016 (3)	−0.005 (2)	0.0046 (17)
C3	0.0394 (17)	0.0395 (15)	0.0365 (15)	0.0018 (17)	−0.0037 (15)	0.0049 (13)
O3	0.0678 (17)	0.0441 (13)	0.0544 (14)	−0.0087 (15)	−0.0043 (15)	0.0031 (11)
C4	0.0452 (19)	0.0366 (16)	0.0385 (16)	0.0016 (15)	0.0020 (16)	0.0092 (13)
O4	0.0605 (16)	0.0383 (12)	0.0364 (11)	−0.0028 (12)	0.0032 (12)	0.0020 (9)
C5	0.0473 (19)	0.0352 (15)	0.0432 (18)	0.0034 (18)	0.0011 (17)	0.0056 (14)
O5	0.0367 (13)	0.0485 (12)	0.0406 (12)	0.0064 (12)	0.0060 (11)	0.0020 (10)
O6	0.0455 (14)	0.0504 (13)	0.0440 (13)	−0.0009 (13)	−0.0044 (12)	0.0163 (11)
C6	0.0328 (16)	0.0358 (15)	0.0378 (15)	0.0055 (15)	0.0032 (14)	0.0039 (13)
C7	0.0293 (15)	0.0367 (15)	0.0326 (15)	−0.0029 (14)	0.0023 (13)	0.0023 (12)
C8	0.054 (2)	0.0394 (16)	0.0345 (16)	0.0045 (19)	0.0078 (17)	0.0044 (14)

Geometric parameters (Å, º) top

O1—C3	1.332 (4)	C4—C5	1.456 (5)
O1—C2	1.462 (4)	O4—C5	1.353 (4)
C1—C2	1.444 (7)	O4—C6	1.432 (4)
C1—H1A	0.9600	O5—C7	1.421 (4)
C1—H1B	0.9600	O5—H5A	0.91 (4)
C1—H1C	0.9600	O6—C8	1.425 (4)
O2—C4	1.356 (4)	O6—H6A	0.87 (5)
O2—H2A	0.83 (3)	C6—C7	1.516 (4)
C2—H2B	0.9700	C6—H6B	0.9800
C2—H2C	0.9700	C7—C8	1.510 (4)
C3—C4	1.332 (5)	C7—H7A	0.9800
C3—C6	1.500 (4)	C8—H8A	0.9700
O3—C5	1.215 (4)	C8—H8B	0.9700

C3—O1—C2	116.5 (3)	O3—C5—C4	129.0 (3)
C2—C1—H1A	109.5	O4—C5—C4	109.9 (3)
C2—C1—H1B	109.5	C7—O5—H5A	107 (3)
H1A—C1—H1B	109.5	C8—O6—H6A	103 (4)
C2—C1—H1C	109.5	O4—C6—C3	104.2 (2)
H1A—C1—H1C	109.5	O4—C6—C7	111.0 (3)
H1B—C1—H1C	109.5	C3—C6—C7	113.8 (3)
C4—O2—H2A	110 (4)	O4—C6—H6B	109.2
C1—C2—O1	109.1 (4)	C3—C6—H6B	109.2
C1—C2—H2B	109.9	C7—C6—H6B	109.2
O1—C2—H2B	109.9	O5—C7—C8	107.7 (3)
C1—C2—H2C	109.9	O5—C7—C6	111.1 (3)
O1—C2—H2C	109.9	C8—C7—C6	110.7 (3)
H2B—C2—H2C	108.3	O5—C7—H7A	109.1
O1—C3—C4	134.8 (3)	C8—C7—H7A	109.1
O1—C3—C6	115.7 (3)	C6—C7—H7A	109.1
C4—C3—C6	109.5 (3)	O6—C8—C7	110.8 (3)
C3—C4—O2	129.9 (3)	O6—C8—H8A	109.5
C3—C4—C5	107.4 (3)	C7—C8—H8A	109.5
O2—C4—C5	122.6 (3)	O6—C8—H8B	109.5
C5—O4—C6	109.1 (2)	C7—C8—H8B	109.5
O3—C5—O4	121.1 (3)	H8A—C8—H8B	108.1

C3—O1—C2—C1	−169.9 (4)	C5—O4—C6—C3	1.1 (3)
C2—O1—C3—C4	3.1 (6)	C5—O4—C6—C7	−121.7 (3)
C2—O1—C3—C6	179.3 (3)	O1—C3—C6—O4	−178.1 (3)
O1—C3—C4—O2	1.1 (6)	C4—C3—C6—O4	−0.9 (4)
C6—C3—C4—O2	−175.3 (3)	O1—C3—C6—C7	−57.1 (4)
O1—C3—C4—C5	176.8 (4)	C4—C3—C6—C7	120.0 (3)
C6—C3—C4—C5	0.4 (4)	O4—C6—C7—O5	61.3 (3)
C6—O4—C5—O3	178.3 (3)	C3—C6—C7—O5	−55.8 (4)
C6—O4—C5—C4	−1.0 (4)	O4—C6—C7—C8	−58.3 (4)
C3—C4—C5—O3	−178.9 (4)	C3—C6—C7—C8	−175.4 (3)
O2—C4—C5—O3	−2.8 (6)	O5—C7—C8—O6	67.1 (4)
C3—C4—C5—O4	0.3 (4)	C6—C7—C8—O6	−171.2 (3)
O2—C4—C5—O4	176.4 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2A···O5ⁱ	0.83 (3)	2.06 (3)	2.873 (3)	168 (5)
O5—H5A···O3ⁱⁱ	0.91 (5)	1.90 (4)	2.748 (4)	154 (4)
O6—H6A···O6ⁱⁱⁱ	0.87 (5)	1.87 (5)	2.715 (4)	163 (4)

Symmetry codes: (i) −x, y−1/2, −z+3/2; (ii) −x, y+1/2, −z+3/2; (iii) x−1/2, −y+3/2, −z+1.

Experimental details

Crystal data
Chemical formula	C₈H₁₂O₆
M_r	204.18
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	293
a, b, c (Å)	4.6690 (9), 11.939 (2), 16.794 (3)
V (Å³)	936.2 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.13
Crystal size (mm)	0.20 × 0.20 × 0.10

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	1973, 1024, 882
R_int	0.028
(sin θ/λ)_max (Å⁻¹)	0.600

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.040, 0.138, 1.00
No. of reflections	1024
No. of parameters	137
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.18, −0.26

Computer programs: CAD-4 Software (Enraf–Nonius, 1989), XCAD4 (Harms & Wocadlo, 1995), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2A···O5ⁱ	0.83 (3)	2.06 (3)	2.873 (3)	168 (5)
O5—H5A···O3ⁱⁱ	0.91 (5)	1.90 (4)	2.748 (4)	154 (4)
O6—H6A···O6ⁱⁱⁱ	0.87 (5)	1.87 (5)	2.715 (4)	163 (4)

Symmetry codes: (i) −x, y−1/2, −z+3/2; (ii) −x, y+1/2, −z+3/2; (iii) x−1/2, −y+3/2, −z+1.

References

Enraf–Nonius (1989). CAD-4 Software. Enraf–Nonius, Delft, The Netherlands. Google Scholar
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Google Scholar
Nihro, Y., Sogawa, S. & Izumi, A. (1992). J. Med. Chem. 35, 1618–1623. CrossRef PubMed CAS Web of Science Google Scholar
Satoh, T., Niino, Y. & Matsumoto, H. (1994). Jpn Patent JP6228557. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar

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CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 64| Part 5| May 2008| Page o860

doi:10.1107/S1600536808009963

Open

access