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

Abstract

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

Related literature

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

Experimental

Crystal data

• C₆H₆O₄

• M _r = 142.11

• Monoclinic,

• a = 6.9400 (14) Å

• b = 6.0648 (12) Å

• c = 14.008 (3) Å

• β = 92.77 (3)°

• V = 588.9 (2) ų

• Z = 4

• Mo Kα radiation

• μ = 0.14 mm⁻¹

• T = 113 (2) K

• 0.14 × 0.12 × 0.10 mm

Data collection

• Rigaku Saturn diffractometer

• Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005 ▶) T _min = 0.981, T _max = 0.986

• 3970 measured reflections

• 1381 independent reflections

• 1166 reflections with I > 2σ(I)

• R _int = 0.025

Refinement

• R[F ² > 2σ(F ²)] = 0.032

• wR(F ²) = 0.096

• S = 1.10

• 1381 reflections

• 115 parameters

• All H-ataom parameters refined

• Δρ_max = 0.37 e Å⁻³

• Δρ_min = −0.24 e Å⁻³

Data collection: CrystalClear (Rigaku/MSC, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; 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.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H6⋯O3i	0.838 (18)	1.89 (2)	2.6902 (12)	159.6 (13)
O2—H5⋯O3ii	0.94 (2)	1.75 (2)	2.6596 (12)	162.6 (17)
O4—H6⋯O3	0.838 (18)	2.44 (2)	2.7820 (12)	105.4 (10)
C1—H3⋯O4	1.005 (15)	2.537 (14)	2.8957 (15)	100.5 (9)
C6—H4⋯O2iii	0.936 (14)	2.412 (13)	3.3354 (14)	169.4 (12)

Symmetry codes: (i) ; (ii) ; (iii) .

supplementary crystallographic information

Comment

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.

Experimental

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

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

Figures

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.

Crystal data

C6H6O4	F000 = 296
Mr = 142.11	Dx = 1.603 Mg m−3
Monoclinic, P21/n	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1620 reflections
a = 6.9400 (14) Å	θ = 1.5–27.9º
b = 6.0648 (12) Å	µ = 0.14 mm−1
c = 14.008 (3) Å	T = 113 (2) K
β = 92.77 (3)º	Block, colorless
V = 588.9 (2) Å3	0.14 × 0.12 × 0.10 mm
Z = 4

Data collection

Rigaku Saturn diffractometer	1381 independent reflections
Radiation source: rotating anode	1166 reflections with I > 2σ(I)
Monochromator: confocal	Rint = 0.025
T = 113(2) K	θmax = 27.9º
ω scans	θmin = 2.9º
Absorption correction: multi-scan(CrystalClear; Rigaku/MSC, 2005)	h = −9→9
Tmin = 0.981, Tmax = 0.986	k = −7→7
3970 measured reflections	l = −10→18

Refinement

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)] = 0.032	All 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 reflections	Δρmax = 0.37 e Å−3
115 parameters	Δρmin = −0.24 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O3	0.27997 (10)	1.01120 (11)	0.27250 (5)	0.0149 (2)
O1	0.76427 (10)	1.05517 (12)	0.44524 (5)	0.0157 (2)
O4	0.56909 (12)	0.69576 (12)	0.26153 (5)	0.0171 (2)
O2	0.32648 (11)	1.36372 (12)	0.40092 (5)	0.0173 (2)
C4	0.43152 (15)	1.02588 (15)	0.32615 (7)	0.0124 (2)
C5	0.46324 (15)	1.20540 (16)	0.39217 (7)	0.0132 (2)
C3	0.58183 (15)	0.86536 (16)	0.32479 (7)	0.0127 (2)
C2	0.74196 (15)	0.88197 (16)	0.38483 (7)	0.0139 (2)
C6	0.62774 (16)	1.21333 (17)	0.44749 (7)	0.0157 (2)
C1	0.90601 (15)	0.72547 (19)	0.39113 (8)	0.0174 (3)
H4	0.656 (2)	1.323 (2)	0.4929 (10)	0.021 (3)*
H3	0.871 (2)	0.582 (2)	0.3585 (10)	0.028 (3)*
H1	1.017 (2)	0.782 (2)	0.3616 (11)	0.037 (4)*
H2	0.940 (2)	0.689 (2)	0.4591 (10)	0.025 (3)*
H5	0.271 (3)	1.393 (3)	0.3397 (14)	0.054 (5)*
H6	0.454 (3)	0.669 (2)	0.2453 (11)	0.037 (4)*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O3	0.0141 (4)	0.0150 (4)	0.0153 (4)	0.0004 (3)	−0.0022 (3)	−0.0013 (3)
O1	0.0155 (4)	0.0165 (4)	0.0148 (4)	−0.0005 (3)	−0.0020 (3)	−0.0020 (3)
O4	0.0136 (4)	0.0163 (4)	0.0211 (4)	0.0004 (3)	−0.0008 (3)	−0.0080 (3)
O2	0.0233 (4)	0.0142 (4)	0.0142 (4)	0.0058 (3)	−0.0018 (3)	−0.0018 (3)
C4	0.0142 (5)	0.0125 (5)	0.0105 (4)	−0.0022 (4)	0.0016 (4)	0.0017 (3)
C5	0.0177 (5)	0.0106 (5)	0.0116 (4)	0.0007 (4)	0.0021 (4)	0.0008 (3)
C3	0.0138 (5)	0.0118 (5)	0.0128 (5)	−0.0019 (4)	0.0023 (4)	−0.0011 (3)
C2	0.0145 (5)	0.0141 (5)	0.0132 (4)	−0.0017 (4)	0.0024 (4)	−0.0003 (3)
C6	0.0200 (6)	0.0133 (5)	0.0139 (5)	−0.0012 (4)	0.0006 (4)	−0.0020 (4)
C1	0.0126 (5)	0.0200 (6)	0.0195 (5)	0.0013 (4)	0.0001 (4)	−0.0010 (4)

Geometric parameters (Å, °)

O3—C4	1.2659 (13)	C4—C5	1.4386 (13)
O1—C6	1.3497 (13)	C5—C6	1.3494 (16)
O1—C2	1.3531 (12)	C3—C2	1.3646 (15)
O4—C3	1.3577 (12)	C2—C1	1.4816 (15)
O4—H6	0.838 (18)	C6—H4	0.936 (14)
O2—C5	1.3598 (12)	C1—H3	1.005 (15)
O2—H5	0.94 (2)	C1—H1	0.956 (17)
C4—C3	1.4276 (14)	C1—H2	0.996 (15)
C6—O1—C2	120.47 (8)	O1—C2—C3	120.53 (9)
C3—O4—H6	110.7 (11)	O1—C2—C1	113.31 (9)
C5—O2—H5	107.9 (12)	C3—C2—C1	126.15 (9)
O3—C4—C3	122.06 (9)	C5—C6—O1	122.45 (9)
O3—C4—C5	122.13 (9)	C5—C6—H4	124.0 (8)
C3—C4—C5	115.82 (9)	O1—C6—H4	113.5 (8)
C6—C5—O2	119.86 (9)	C2—C1—H3	111.1 (8)
C6—C5—C4	119.68 (10)	C2—C1—H1	112.2 (9)
O2—C5—C4	120.44 (9)	H3—C1—H1	107.1 (13)
O4—C3—C2	118.92 (9)	C2—C1—H2	110.3 (8)
O4—C3—C4	120.04 (9)	H3—C1—H2	106.4 (12)
C2—C3—C4	121.01 (9)	H1—C1—H2	109.5 (13)
O3—C4—C5—C6	−179.79 (9)	C6—O1—C2—C1	179.47 (9)
C3—C4—C5—C6	0.12 (14)	O4—C3—C2—O1	176.47 (9)
O3—C4—C5—O2	1.94 (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—O4	3.12 (15)	C4—C3—C2—C1	179.21 (9)
C5—C4—C3—O4	−176.78 (8)	O2—C5—C6—O1	176.71 (9)
O3—C4—C3—C2	−178.50 (9)	C4—C5—C6—O1	−1.58 (15)
C5—C4—C3—C2	1.59 (14)	C2—O1—C6—C5	1.32 (15)
C6—O1—C2—C3	0.47 (15)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H6···O3i	0.838 (18)	1.89 (2)	2.6902 (12)	159.6 (13)
O2—H5···O3ii	0.94 (2)	1.75 (2)	2.6596 (12)	162.6 (17)
O4—H6···O3	0.838 (18)	2.44 (2)	2.7820 (12)	105.4 (10)
C1—H3···O4	1.005 (15)	2.537 (14)	2.8957 (15)	100.5 (9)
C6—H4···O2iii	0.936 (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.