5-Hydr-oxy-2-methyl-4H-pyran-4-one.

The title compound, C(6)H(6)O(3), is a member of the pyrone family. The mol-ecules are planar (r.m.s. deviation of the asymmetric unit is 0.0248 Å, whereas that of the dimer is 0.0360 Å) and they are dimerized due to inter-molecular O-H⋯O hydrogen bonds. The dimers are connected to each other through hydrogen bonds involving the CH(3) group and the hydr-oxy O atom. There are π-π inter-actions between the centroids of the pyrone rings at a distance of 3.8552 (13) Å. A C-H⋯π inter-action also exists between the carbonyl group and the centroid CgA of the pyrone ring, with O⋯CgA = 3.65 (1) Å and C⋯CgA = 4.363 (2) Å.

Related literature

For general background, see: Aytemir et al. (1999 ▶); Erol & Yulug (1999 ▶). For studies involving metal complexes of allomaltol, see: Ma et al. (2004 ▶); Shaheen et al. (2008 ▶, 2008a ▶). For crystal structures of related compounds, see: Tak et al. (1994 ▶); Rahman et al. (1997 ▶).

Experimental

Crystal data

C6H6O3

M = 126.11

Triclinic,

a = 5.4467 (4) Å

b = 7.3301 (5) Å

c = 7.6945 (5) Å

α = 105.354 (3)°

β = 98.416 (4)°

γ = 100.008 (4)°

V = 285.68 (4) Å3

Z = 2

Mo Kα radiation

μ = 0.12 mm−1

T = 296 (2) K

0.22 × 0.20 × 0.10 mm

Data collection

Bruker Kappa APEXII CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T min = 0.970, T max = 0.986

6426 measured reflections

1504 independent reflections

713 reflections with I > 2σ(I)

R int = 0.045

Refinement

R[F 2 > 2σ(F 2)] = 0.053

wR(F 2) = 0.131

S = 1.00

1504 reflections

87 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.18 e Å−3

Δρmin = −0.20 e Å−3

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2007 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶) and PLATON (Spek, 2003 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809003158/at2715sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809003158/at2715Isup2.hkl

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

C6H6O3	Z = 2
Mr = 126.11	F(000) = 132
Triclinic, P1	Dx = 1.466 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.4467 (4) Å	Cell parameters from 1504 reflections
b = 7.3301 (5) Å	θ = 2.8–29.1°
c = 7.6945 (5) Å	µ = 0.12 mm−1
α = 105.354 (3)°	T = 296 K
β = 98.416 (4)°	Prismatic, colourless
γ = 100.008 (4)°	0.22 × 0.20 × 0.10 mm
V = 285.68 (4) Å3

Bruker Kappa APEXII CCD diffractometer	1504 independent reflections
Radiation source: fine-focus sealed tube	713 reflections with I > 2σ(I)
graphite	Rint = 0.045
Detector resolution: 7.40 pixels mm-1	θmax = 29.1°, θmin = 2.8°
ω scans	h = −7→7
Absorption correction: multi-scan (SADABS; Bruker, 2005)	k = −9→9
Tmin = 0.970, Tmax = 0.986	l = −10→10
6426 measured reflections

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)] = 0.053	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.131	w = 1/[σ2(Fo2) + (0.0523P)2 + 0.0219P] where P = (Fo2 + 2Fc2)/3
S = 1.00	(Δ/σ)max < 0.001
1504 reflections	Δρmax = 0.18 e Å−3
87 parameters	Δρmin = −0.20 e Å−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.053 (14)

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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.

	x	y	z	Uiso*/Ueq
O1	0.2557 (3)	0.3634 (2)	0.37275 (16)	0.0542 (5)
O2	−0.1534 (3)	0.1916 (2)	0.64758 (18)	0.0641 (6)
O3	−0.4440 (3)	0.0215 (2)	0.29282 (18)	0.0631 (6)
C1	0.1595 (4)	0.3242 (3)	0.5153 (3)	0.0554 (8)
C2	−0.0705 (4)	0.2171 (3)	0.4961 (3)	0.0467 (7)
C3	−0.2315 (4)	0.1292 (3)	0.3153 (3)	0.0455 (7)
C4	−0.1223 (4)	0.1770 (3)	0.1711 (3)	0.0486 (7)
C5	0.1096 (4)	0.2896 (3)	0.2016 (3)	0.0463 (7)
C6	0.2424 (4)	0.3492 (4)	0.0642 (3)	0.0624 (8)
H1	0.26084	0.37532	0.63280	0.0664*
H2	−0.299 (5)	0.111 (4)	0.628 (3)	0.0769*
H4	−0.21633	0.12780	0.05123	0.0584*
H6A	0.13508	0.29403	−0.05590	0.0936*
H6B	0.28060	0.48817	0.09427	0.0936*
H6C	0.39779	0.30418	0.06523	0.0936*

	U11	U22	U33	U12	U13	U23
O1	0.0501 (9)	0.0655 (10)	0.0377 (8)	−0.0005 (7)	−0.0002 (6)	0.0131 (7)
O2	0.0703 (11)	0.0723 (12)	0.0356 (8)	−0.0115 (9)	0.0030 (7)	0.0143 (8)
O3	0.0506 (10)	0.0853 (12)	0.0440 (8)	−0.0041 (9)	0.0051 (7)	0.0182 (8)
C1	0.0612 (15)	0.0605 (15)	0.0346 (10)	0.0001 (12)	−0.0004 (10)	0.0117 (10)
C2	0.0540 (14)	0.0473 (13)	0.0343 (10)	0.0071 (11)	0.0035 (9)	0.0101 (9)
C3	0.0410 (13)	0.0519 (14)	0.0391 (11)	0.0078 (11)	0.0038 (9)	0.0099 (9)
C4	0.0457 (13)	0.0612 (15)	0.0327 (9)	0.0077 (11)	0.0027 (9)	0.0089 (10)
C5	0.0454 (13)	0.0544 (14)	0.0343 (10)	0.0090 (11)	0.0033 (9)	0.0091 (9)
C6	0.0547 (14)	0.0819 (17)	0.0488 (12)	0.0074 (12)	0.0110 (10)	0.0210 (12)

O1—C1	1.358 (3)	C4—C5	1.334 (3)
O1—C5	1.352 (3)	C5—C6	1.480 (3)
O2—C2	1.356 (3)	C1—H1	0.9300
O3—C3	1.243 (3)	C4—H4	0.9300
O2—H2	0.87 (3)	C6—H6A	0.9600
C1—C2	1.323 (3)	C6—H6B	0.9600
C2—C3	1.446 (3)	C6—H6C	0.9600
C3—C4	1.426 (3)
O1···O3i	3.200 (2)	C2···O1iii	3.350 (3)
O1···O1ii	3.078 (2)	C2···O2vi	3.405 (3)
O1···C2iii	3.350 (3)	C2···C1iii	3.501 (3)
O2···O3	2.7853 (19)	C2···C2vi	3.415 (3)
O2···C6iv	3.378 (3)	C6···O2ix	3.378 (3)
O2···O3v	2.635 (2)	C3···H2v	3.00 (3)
O2···C2vi	3.405 (3)	C4···H6Cvii	3.0000
O3···O2v	2.635 (2)	H2···O3	2.46 (2)
O3···O1vii	3.200 (2)	H2···O3v	1.83 (3)
O3···O2	2.7853 (19)	H2···C3v	3.00 (3)
O2···H6Biii	2.9000	H4···H6A	2.4500
O2···H6Aiv	2.4200	H4···O3viii	2.8200
O3···H2	2.46 (2)	H6A···O2ix	2.4200
O3···H2v	1.83 (3)	H6A···H4	2.4500
O3···H4viii	2.8200	H6B···O2iii	2.9000
C1···C1iii	3.387 (3)	H6C···C4i	3.0000
C1···C2iii	3.501 (3)
C1—O1—C5	118.57 (18)	O1—C5—C4	121.3 (2)
C2—O2—H2	116.2 (15)	O1—C1—H1	118.00
O1—C1—C2	123.6 (2)	C2—C1—H1	118.00
O2—C2—C3	120.55 (19)	C3—C4—H4	119.00
C1—C2—C3	120.2 (2)	C5—C4—H4	119.00
O2—C2—C1	119.3 (2)	C5—C6—H6A	109.00
O3—C3—C4	124.7 (2)	C5—C6—H6B	109.00
C2—C3—C4	113.9 (2)	C5—C6—H6C	109.00
O3—C3—C2	121.4 (2)	H6A—C6—H6B	109.00
C3—C4—C5	122.5 (2)	H6A—C6—H6C	109.00
O1—C5—C6	111.28 (19)	H6B—C6—H6C	109.00
C4—C5—C6	127.5 (2)
C5—O1—C1—C2	0.0 (3)	C1—C2—C3—O3	177.0 (2)
C1—O1—C5—C4	−1.4 (3)	C1—C2—C3—C4	−2.6 (3)
C1—O1—C5—C6	179.1 (2)	O3—C3—C4—C5	−178.3 (2)
O1—C1—C2—O2	−177.69 (19)	C2—C3—C4—C5	1.3 (3)
O1—C1—C2—C3	2.0 (4)	C3—C4—C5—O1	0.7 (4)
O2—C2—C3—O3	−3.3 (3)	C3—C4—C5—C6	−179.9 (2)
O2—C2—C3—C4	177.2 (2)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O3	0.87 (3)	2.46 (2)	2.7853 (19)	103.1 (18)
O2—H2···O3v	0.87 (3)	1.83 (3)	2.635 (2)	152 (2)
C6—H6A···O2ix	0.9600	2.4200	3.378 (3)	173.00
C3—O3···CgAvii	1.243 (3)	3.6465 (19)	4.363 (2)	117.56 (13)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯O3	0.87 (3)	2.46 (2)	2.7853 (19)	103.1 (18)
O2—H2⋯O3i	0.87 (3)	1.83 (3)	2.635 (2)	152 (2)
C6—H6A⋯O2ii	0.96	2.42	3.378 (3)	173

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