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Acta Cryst. (2008). E64, o1032    [ doi:10.1107/S1600536808010957 ]

3,5-Dihydroxy-2-methyl-4H-pyran-4-one

C.-M. Dong, S.-C Pu and W.-Y. Gao

Abstract top

In the title compound, C6H6O4, inter- and intramolecular hydrogen bonds are observed which help to establish the crystal structure. There are weak [pi]-[pi] interactions between pyran rings separated by 3.5692 (9) Å.

Comment top

The title compound, 3,5-dihydroxy-2-methyl-pyran-4-one, (I) was identified as a decomposition product in the stored solution of orange juice (Shinoda, et al., 2004). We report here the crystal structure of the title compound (Fig. 1) which was isolated from Hydrocotyle sibthorpoioides Lam. The structure of (I) is stabilized by two strong intermolecular hydrogen bonds of the type O—H···O and a weak intermolecular interaction of the type C—H···O. Intramolecular interactions are also observed which result in five membered rings; details are given in Table 1. There is indication of π-π interactions between the pyran rings lying about inversion centers with minimum separation of 3.5692 (9) Å. The crystal structures of 2-hydroxymethyl analogue (Yao et al., 2005) and 5-hydroxy-3-methoxy-pyran-4-one (Gibbons et al., 2000) have been reported.

Related literature top

For general background, see:Shinoda et al. (2004). For related structures, see: Yao et al. (2005; Gibbons et al. (2000).

Experimental top

Dried powder of Hydrocotyle sibthorpoioides Lam was exacted with EtOH and the extract was concentrated in vacuo. The residue was subjected to silical-gel coloumn chromatography. Elution with chloroform-methanol (95:5 v/v) yielded the title compound. Crystals suitable for XRD study were grwon from a solution of methanol at room temperature by slow evaporation.

Refinement top

All H atoms were located from difference map and allowed to refine freely.

Computing details top

Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: CrystalClear (Rigaku/MSC, 2005); data reduction: CrystalClear (Rigaku/MSC, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. A view of the molecule of (I). Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii.
3,5-Dihydroxy-2-methyl-4H-pyran-4-one top
Crystal data top
C6H6O4F000 = 296
Mr = 142.11Dx = 1.603 Mg m−3
Monoclinic, P21/nMo Kα radiation
λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 1620 reflections
a = 6.9400 (14) Åθ = 1.5–27.9º
b = 6.0648 (12) ŵ = 0.14 mm−1
c = 14.008 (3) ÅT = 113 (2) K
β = 92.77 (3)ºBlock, colorless
V = 588.9 (2) Å30.14 × 0.12 × 0.10 mm
Z = 4
Data collection top
Rigaku Saturn
diffractometer		1381 independent reflections
Radiation source: rotating anode1166 reflections with I > 2σ(I)
Monochromator: confocalRint = 0.025
T = 113(2) Kθmax = 27.9º
ω scansθmin = 2.9º
Absorption correction: multi-scan
(CrystalClear; Rigaku/MSC, 2005)		h = −9→9
Tmin = 0.981, Tmax = 0.986k = −7→7
3970 measured reflectionsl = −10→18
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.032All H-atom parameters refined
wR(F2) = 0.096  w = 1/[σ2(Fo2) + (0.0654P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.11(Δ/σ)max < 0.001
1381 reflectionsΔρmax = 0.37 e Å−3
115 parametersΔρmin = −0.24 e Å−3
Primary atom site location: structure-invariant direct methodsExtinction correction: none
Crystal data top
C6H6O4V = 588.9 (2) Å3
Mr = 142.11Z = 4
Monoclinic, P21/nMo Kα
a = 6.9400 (14) ŵ = 0.14 mm−1
b = 6.0648 (12) ÅT = 113 (2) K
c = 14.008 (3) Å0.14 × 0.12 × 0.10 mm
β = 92.77 (3)º
Data collection top
Rigaku Saturn
diffractometer		1381 independent reflections
Absorption correction: multi-scan
(CrystalClear; Rigaku/MSC, 2005)		1166 reflections with I > 2σ(I)
Tmin = 0.981, Tmax = 0.986Rint = 0.025
3970 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.032115 parameters
wR(F2) = 0.096All H-atom parameters refined
S = 1.11Δρmax = 0.37 e Å−3
1381 reflectionsΔρmin = −0.24 e Å−3
Special details top

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
xyzUiso*/Ueq
O30.27997 (10)1.01120 (11)0.27250 (5)0.0149 (2)
O10.76427 (10)1.05517 (12)0.44524 (5)0.0157 (2)
O40.56909 (12)0.69576 (12)0.26153 (5)0.0171 (2)
O20.32648 (11)1.36372 (12)0.40092 (5)0.0173 (2)
C40.43152 (15)1.02588 (15)0.32615 (7)0.0124 (2)
C50.46324 (15)1.20540 (16)0.39217 (7)0.0132 (2)
C30.58183 (15)0.86536 (16)0.32479 (7)0.0127 (2)
C20.74196 (15)0.88197 (16)0.38483 (7)0.0139 (2)
C60.62774 (16)1.21333 (17)0.44749 (7)0.0157 (2)
C10.90601 (15)0.72547 (19)0.39113 (8)0.0174 (3)
H40.656 (2)1.323 (2)0.4929 (10)0.021 (3)*
H30.871 (2)0.582 (2)0.3585 (10)0.028 (3)*
H11.017 (2)0.782 (2)0.3616 (11)0.037 (4)*
H20.940 (2)0.689 (2)0.4591 (10)0.025 (3)*
H50.271 (3)1.393 (3)0.3397 (14)0.054 (5)*
H60.454 (3)0.669 (2)0.2453 (11)0.037 (4)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O30.0141 (4)0.0150 (4)0.0153 (4)0.0004 (3)−0.0022 (3)−0.0013 (3)
O10.0155 (4)0.0165 (4)0.0148 (4)−0.0005 (3)−0.0020 (3)−0.0020 (3)
O40.0136 (4)0.0163 (4)0.0211 (4)0.0004 (3)−0.0008 (3)−0.0080 (3)
O20.0233 (4)0.0142 (4)0.0142 (4)0.0058 (3)−0.0018 (3)−0.0018 (3)
C40.0142 (5)0.0125 (5)0.0105 (4)−0.0022 (4)0.0016 (4)0.0017 (3)
C50.0177 (5)0.0106 (5)0.0116 (4)0.0007 (4)0.0021 (4)0.0008 (3)
C30.0138 (5)0.0118 (5)0.0128 (5)−0.0019 (4)0.0023 (4)−0.0011 (3)
C20.0145 (5)0.0141 (5)0.0132 (4)−0.0017 (4)0.0024 (4)−0.0003 (3)
C60.0200 (6)0.0133 (5)0.0139 (5)−0.0012 (4)0.0006 (4)−0.0020 (4)
C10.0126 (5)0.0200 (6)0.0195 (5)0.0013 (4)0.0001 (4)−0.0010 (4)
Geometric parameters (Å, °) top
O3—C41.2659 (13)C4—C51.4386 (13)
O1—C61.3497 (13)C5—C61.3494 (16)
O1—C21.3531 (12)C3—C21.3646 (15)
O4—C31.3577 (12)C2—C11.4816 (15)
O4—H60.838 (18)C6—H40.936 (14)
O2—C51.3598 (12)C1—H31.005 (15)
O2—H50.94 (2)C1—H10.956 (17)
C4—C31.4276 (14)C1—H20.996 (15)
C6—O1—C2120.47 (8)O1—C2—C3120.53 (9)
C3—O4—H6110.7 (11)O1—C2—C1113.31 (9)
C5—O2—H5107.9 (12)C3—C2—C1126.15 (9)
O3—C4—C3122.06 (9)C5—C6—O1122.45 (9)
O3—C4—C5122.13 (9)C5—C6—H4124.0 (8)
C3—C4—C5115.82 (9)O1—C6—H4113.5 (8)
C6—C5—O2119.86 (9)C2—C1—H3111.1 (8)
C6—C5—C4119.68 (10)C2—C1—H1112.2 (9)
O2—C5—C4120.44 (9)H3—C1—H1107.1 (13)
O4—C3—C2118.92 (9)C2—C1—H2110.3 (8)
O4—C3—C4120.04 (9)H3—C1—H2106.4 (12)
C2—C3—C4121.01 (9)H1—C1—H2109.5 (13)
O3—C4—C5—C6−179.79 (9)C6—O1—C2—C1179.47 (9)
C3—C4—C5—C60.12 (14)O4—C3—C2—O1176.47 (9)
O3—C4—C5—O21.94 (15)C4—C3—C2—O1−1.93 (15)
C3—C4—C5—O2−178.15 (8)O4—C3—C2—C1−2.39 (16)
O3—C4—C3—O43.12 (15)C4—C3—C2—C1179.21 (9)
C5—C4—C3—O4−176.78 (8)O2—C5—C6—O1176.71 (9)
O3—C4—C3—C2−178.50 (9)C4—C5—C6—O1−1.58 (15)
C5—C4—C3—C21.59 (14)C2—O1—C6—C51.32 (15)
C6—O1—C2—C30.47 (15)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O4—H6···O3i0.838 (18)1.89 (2)2.6902 (12)159.6 (13)
O2—H5···O3ii0.94 (2)1.75 (2)2.6596 (12)162.6 (17)
O4—H6···O30.838 (18)2.44 (2)2.7820 (12)105.4 (10)
C1—H3···O41.005 (15)2.537 (14)2.8957 (15)100.5 (9)
C6—H4···O2iii0.936 (14)2.412 (13)3.3354 (14)169.4 (12)
Symmetry codes: (i) −x+1/2, y−1/2, −z+1/2; (ii) −x+1/2, y+1/2, −z+1/2; (iii) −x+1, −y+3, −z+1.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O4—H6···O3i0.838 (18)1.89 (2)2.6902 (12)159.6 (13)
O2—H5···O3ii0.94 (2)1.75 (2)2.6596 (12)162.6 (17)
O4—H6···O30.838 (18)2.44 (2)2.7820 (12)105.4 (10)
C1—H3···O41.005 (15)2.537 (14)2.8957 (15)100.5 (9)
C6—H4···O2iii0.936 (14)2.412 (13)3.3354 (14)169.4 (12)
Symmetry codes: (i) −x+1/2, y−1/2, −z+1/2; (ii) −x+1/2, y+1/2, −z+1/2; (iii) −x+1, −y+3, −z+1.
references
References top

Gibbons, S., Denny, B. J., Ali-Amine, S., Mathew, K. T., Skelton, B. W., White, A. H. & Gray, A. I. (2000). J. Nat. Prod. 63, 839–840.

Rigaku/MSC. (2005). CrystalClear. Rigaku/MSC, The Woodlands, Texas, USA.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Shinoda, Y., Murata, M., Homma, S. & Komura, H. (2004). Biosci. Biotechnol. Biochem. 68, 529–536.

Yao, G.-M., Wang, Y.-B., Wang, L.-Q. & Qin, G.-W. (2005). Acta Cryst. E61, o1403–o1405.