3,4,5-Trimethoxy­benzoic acid

Qadeer, G.; Rama, N.H.; Taş, M.; Yeşilel, O.Z.; Wong, W.-Y.

doi:10.1107/S1600536807033429

3,4,5-Trimethoxybenzoic acid

G. Qadeer, N. H. Rama, M. Taş, O. Z. Yeşilel and W.-Y. Wong

The asymmetric unit of the title compound, C₁₀H₁₂O₅, contains two crystallographically independent molecules. In the crystal structure, intermolecular C—H

O and O—H

O hydrogen bonds link the molecules.

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807033429/hk2288sup1.cif Contains datablocks I, global
	Structure factor file (CIF format) https://doi.org/10.1107/S1600536807033429/hk2288Isup2.hkl Contains datablock I

CCDC reference: 657733

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Key indicators

Single-crystal X-ray study
T = 298 K
Mean (C-C) = 0.004 Å
R factor = 0.039
wR factor = 0.094
Data-to-parameter ratio = 8.9

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.26
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.20

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           28.28
           From the CIF: _reflns_number_total               2510
           Count of symmetry unique reflns         2522
           Completeness (_total/calc)             99.52%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          3

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

Comment top

ortho-Alkoxybenzoic acids are a class of acids which crystallize with different packing modes. The distinctive behaviour of 2-ethoxybenzoic acid which forms monomers is due to the formation of an intramolecular hydrogen bond (Gopalakrishna & Cartz, 1972). 2,3-Dimethoxybenzoic acid forms the normal acid dimer pattern (Bryan & White, 1982a). 2,6- Dimethoxybenzoic acid (Bryan & White, 1982b) and 2,6-dimethoxy-3-nitrobenzoic acid (Frankenbach et al., 1991) form catemers. The carboxyl group of 2,6-dimethoxybenzoic acid exists in an anti conformation, while the carboxyl group of 2,6-dimethoxy-3-nitrobenzoic acid in a syn conformation. We report herein the crystal structure of the title compound, (I).

The asymmetric unit of the title compound, (I), (Fig. 1) contains two crystallographicaly independent molecules, in which the bond lengths and angles are generally within normal ranges (Allen et al., 1987). The C—O bonds of the carboxyl groups (Table 1) are compatible with the corresponding values in similar structure (Khan et al., 2006), and smaller than those usually observed in carboxylic acid [1.365 Å]. The valence angles C3—C2—C7 [121.5 (3)°] and C13—C12—C17 [121.9 (2)°] are larger than the standard value of 120°, due to the presence of methoxy and carboxyl groups.

In the crystal structure, the intermolecular O—H···O hydrogen bonds (Table 2) form catemers, as observed in 2,6-dimethoxybenzoic acid and 2,6-dimethoxy-3 -nitrobenzoic acid, the intermolecular C—H···O and O—H···O hydrogen bonds (Table 2, Fig. 2) link the molecules, in which they seem to be effective in the stabilization of the structure.

Related literature top

For related literature, see: Gopalakrishna & Cartz (1972); Bryan & White (1982a,b); Frankenbach et al. (1991); Khan et al. (2006). For bond-length data, see: Allen et al. (1987).

Experimental top

The title compound was purchased and crystallized from ethyl acetate by slow evaporation.

Structure description top

For related literature, see: Gopalakrishna & Cartz (1972); Bryan & White (1982a,b); Frankenbach et al. (1991); Khan et al. (2006). For bond-length data, see: Allen et al. (1987).

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2; data reduction: APEX2; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. A partial packing diagram of (I). Hydrogen bonds are shown as dashed lines.

3,4,5-Trimethoxybenzoic acid top

Crystal data top

C₁₀H₁₂O₅	F(000) = 448
M_r = 212.20	D_x = 1.389 Mg m⁻³
Monoclinic, Pc	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P -2yc	Cell parameters from 1520 reflections
a = 7.3384 (3) Å	θ = 2.8–22.6°
b = 8.8325 (3) Å	µ = 0.11 mm⁻¹
c = 15.7560 (5) Å	T = 298 K
β = 96.576 (2)°	Monoclinic, colourless
V = 1014.53 (6) Å³	0.25 × 0.15 × 0.13 mm
Z = 4

Data collection top

Bruker APEXII area-detector diffractometer	2510 independent reflections
Radiation source: fine-focus sealed tube	1563 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.032
φ and ω scans	θ_max = 28.3°, θ_min = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −8→9
T_min = 0.935, T_max = 0.984	k = −11→11
7599 measured reflections	l = −21→20

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)] = 0.039	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.094	w = 1/[σ²(F_o²) + (0.0445P)²] where P = (F_o² + 2F_c²)/3
S = 1.06	(Δ/σ)_max < 0.001
2510 reflections	Δρ_max = 0.18 e Å⁻³
281 parameters	Δρ_min = −0.17 e Å⁻³
3 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.015 (2)

Crystal data top

C₁₀H₁₂O₅	V = 1014.53 (6) Å³
M_r = 212.20	Z = 4
Monoclinic, Pc	Mo Kα radiation
a = 7.3384 (3) Å	µ = 0.11 mm⁻¹
b = 8.8325 (3) Å	T = 298 K
c = 15.7560 (5) Å	0.25 × 0.15 × 0.13 mm
β = 96.576 (2)°

Data collection top

Bruker APEXII area-detector diffractometer	2510 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	1563 reflections with I > 2σ(I)
T_min = 0.935, T_max = 0.984	R_int = 0.032
7599 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.039	3 restraints
wR(F²) = 0.094	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	Δρ_max = 0.18 e Å⁻³
2510 reflections	Δρ_min = −0.17 e Å⁻³
281 parameters

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

	x	y	z	U_iso*/U_eq
C1	−0.1652 (4)	0.4366 (4)	−0.11562 (19)	0.0433 (7)
C2	−0.0769 (4)	0.3669 (4)	−0.03518 (17)	0.0395 (7)
C3	−0.0469 (4)	0.2135 (4)	−0.03295 (19)	0.0441 (7)
H3	−0.0773	0.1551	−0.0816	0.053*
C4	0.0301 (4)	0.1455 (4)	0.04333 (18)	0.0443 (8)
C5	0.0762 (4)	0.2341 (4)	0.11517 (18)	0.0445 (7)
C6	0.0479 (4)	0.3899 (4)	0.11177 (18)	0.0468 (8)
C7	−0.0298 (4)	0.4573 (4)	0.03633 (18)	0.0447 (7)
C8	0.0387 (6)	−0.0963 (4)	−0.0221 (2)	0.0709 (11)
H8A	0.0682	−0.1996	−0.0074	0.106*
H8B	0.1169	−0.0610	−0.0627	0.106*
H8C	−0.0870	−0.0898	−0.0465	0.106*
C9	0.0388 (5)	0.0870 (5)	0.2365 (2)	0.0827 (13)
H9A	0.1068	0.0464	0.2871	0.124*
H9B	−0.0155	0.0056	0.2020	0.124*
H9C	−0.0560	0.1526	0.2523	0.124*
C10	0.1072 (6)	0.6268 (4)	0.1798 (2)	0.0699 (10)
H10A	0.1452	0.6680	0.2354	0.105*
H10B	−0.0122	0.6651	0.1592	0.105*
H10C	0.1933	0.6558	0.1412	0.105*
C11	0.6042 (4)	0.3894 (3)	0.17572 (18)	0.0413 (7)
C12	0.5381 (4)	0.3165 (3)	0.09221 (17)	0.0389 (7)
C13	0.4686 (4)	0.4063 (3)	0.02396 (17)	0.0417 (7)
H13	0.4595	0.5106	0.0303	0.050*
C14	0.4126 (4)	0.3378 (3)	−0.05409 (17)	0.0414 (7)
C15	0.4295 (4)	0.1813 (4)	−0.06306 (18)	0.0431 (7)
C16	0.4987 (4)	0.0940 (4)	0.00702 (19)	0.0454 (7)
C17	0.5527 (4)	0.1624 (3)	0.08492 (18)	0.0419 (7)
H17	0.5984	0.1044	0.1318	0.050*
C18	0.3239 (5)	0.5732 (4)	−0.1208 (2)	0.0571 (8)
H18A	0.2743	0.6122	−0.1755	0.086*
H18B	0.4418	0.6179	−0.1043	0.086*
H18C	0.2428	0.5973	−0.0791	0.086*
C19	0.4960 (6)	0.0527 (5)	−0.1884 (2)	0.0837 (12)
H19A	0.4354	0.0096	−0.2400	0.126*
H19B	0.5644	−0.0246	−0.1559	0.126*
H19C	0.5780	0.1312	−0.2024	0.126*
C20	0.5773 (7)	−0.1522 (4)	0.0628 (3)	0.0877 (14)
H20A	0.5782	−0.2558	0.0445	0.132*
H20B	0.4990	−0.1419	0.1072	0.132*
H20C	0.6996	−0.1216	0.0840	0.132*
O1	−0.2149 (3)	0.3553 (3)	−0.17842 (12)	0.0592 (6)
O2	−0.1847 (3)	0.5806 (3)	−0.11614 (14)	0.0617 (6)
H2	−0.2344	0.6076	−0.1630	0.093*
O3	0.0653 (3)	−0.0053 (3)	0.05251 (14)	0.0598 (6)
O4	0.1584 (3)	0.1701 (3)	0.18945 (13)	0.0590 (7)
O5	0.1003 (4)	0.4673 (3)	0.18502 (13)	0.0628 (6)
O6	0.6062 (4)	0.5329 (2)	0.17925 (14)	0.0608 (6)
O7	0.6579 (3)	0.3066 (2)	0.23837 (12)	0.0541 (6)
O8	0.3429 (3)	0.4135 (2)	−0.12612 (13)	0.0558 (6)
O9	0.3628 (3)	0.1150 (3)	−0.13918 (13)	0.0575 (6)
O10	0.5106 (3)	−0.0589 (3)	−0.00757 (14)	0.0615 (6)
H6	0.661 (7)	0.568 (6)	0.234 (2)	0.14 (2)*
H7	−0.064 (4)	0.565 (4)	0.0350 (18)	0.046 (8)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0456 (18)	0.051 (2)	0.0310 (15)	−0.0060 (15)	−0.0047 (12)	0.0086 (13)
C2	0.0339 (16)	0.054 (2)	0.0291 (14)	−0.0009 (13)	−0.0029 (12)	0.0098 (13)
C3	0.0480 (18)	0.051 (2)	0.0318 (15)	−0.0043 (14)	−0.0010 (13)	0.0044 (12)
C4	0.046 (2)	0.0479 (19)	0.0378 (17)	0.0009 (14)	−0.0010 (13)	0.0063 (14)
C5	0.0430 (17)	0.057 (2)	0.0313 (16)	0.0000 (15)	−0.0046 (13)	0.0122 (14)
C6	0.0467 (19)	0.058 (2)	0.0333 (16)	−0.0025 (15)	−0.0047 (14)	0.0053 (13)
C7	0.0487 (17)	0.051 (2)	0.0329 (15)	0.0030 (15)	−0.0043 (12)	0.0086 (13)
C8	0.099 (3)	0.058 (2)	0.055 (2)	0.002 (2)	0.007 (2)	−0.0005 (16)
C9	0.080 (3)	0.116 (4)	0.053 (2)	0.021 (2)	0.0102 (19)	0.042 (2)
C10	0.097 (3)	0.060 (2)	0.0473 (19)	−0.006 (2)	−0.0164 (18)	−0.0026 (16)
C11	0.0448 (17)	0.0470 (19)	0.0298 (14)	−0.0001 (14)	−0.0052 (12)	−0.0052 (13)
C12	0.0369 (17)	0.049 (2)	0.0292 (15)	−0.0046 (13)	−0.0028 (12)	−0.0073 (13)
C13	0.0453 (17)	0.0470 (19)	0.0309 (15)	−0.0012 (14)	−0.0039 (12)	−0.0043 (12)
C14	0.0424 (18)	0.051 (2)	0.0284 (16)	−0.0046 (14)	−0.0050 (13)	−0.0028 (13)
C15	0.0448 (17)	0.0515 (19)	0.0314 (15)	−0.0060 (14)	−0.0030 (13)	−0.0094 (13)
C16	0.0482 (19)	0.0428 (18)	0.0441 (18)	−0.0072 (15)	0.0007 (14)	−0.0076 (14)
C17	0.0492 (19)	0.043 (2)	0.0317 (15)	0.0009 (14)	−0.0010 (13)	0.0005 (12)
C18	0.066 (2)	0.059 (2)	0.0427 (18)	0.0059 (18)	−0.0086 (14)	0.0063 (15)
C19	0.087 (3)	0.114 (3)	0.053 (2)	−0.024 (2)	0.0203 (19)	−0.038 (2)
C20	0.139 (4)	0.045 (2)	0.073 (3)	−0.005 (2)	−0.016 (3)	0.0014 (18)
O1	0.0769 (16)	0.0596 (14)	0.0354 (12)	−0.0041 (12)	−0.0178 (10)	0.0064 (10)
O2	0.0873 (17)	0.0527 (16)	0.0389 (12)	0.0024 (13)	−0.0192 (10)	0.0081 (10)
O3	0.0867 (17)	0.0501 (15)	0.0410 (13)	0.0093 (12)	0.0007 (11)	0.0095 (10)
O4	0.0598 (14)	0.0743 (17)	0.0388 (13)	0.0058 (11)	−0.0125 (10)	0.0168 (11)
O5	0.0889 (17)	0.0606 (15)	0.0329 (12)	−0.0023 (13)	−0.0195 (11)	0.0012 (9)
O6	0.0958 (18)	0.0425 (14)	0.0385 (13)	0.0029 (12)	−0.0162 (11)	−0.0090 (9)
O7	0.0741 (15)	0.0502 (14)	0.0334 (11)	−0.0018 (11)	−0.0132 (10)	−0.0021 (9)
O8	0.0729 (16)	0.0597 (16)	0.0300 (11)	0.0019 (12)	−0.0152 (10)	−0.0018 (9)
O9	0.0653 (15)	0.0680 (15)	0.0359 (12)	−0.0065 (11)	−0.0083 (10)	−0.0180 (10)
O10	0.0888 (18)	0.0434 (13)	0.0489 (13)	−0.0058 (12)	−0.0066 (11)	−0.0093 (10)

Geometric parameters (Å, º) top

C1—O1	1.243 (4)	C11—O6	1.269 (3)
C1—O2	1.279 (4)	C11—C12	1.495 (4)
C1—C2	1.489 (4)	C12—C17	1.372 (4)
C2—C3	1.373 (4)	C12—C13	1.386 (4)
C2—C7	1.392 (4)	C13—C14	1.390 (4)
C3—C4	1.403 (4)	C13—H13	0.9300
C3—H3	0.9300	C14—O8	1.365 (3)
C4—O3	1.361 (4)	C14—C15	1.396 (4)
C4—C5	1.386 (4)	C15—O9	1.374 (3)
C5—O4	1.375 (3)	C15—C16	1.394 (4)
C5—C6	1.391 (4)	C16—O10	1.374 (4)
C6—O5	1.359 (4)	C16—C17	1.385 (4)
C6—C7	1.392 (4)	C17—H17	0.9300
C7—H7	0.99 (3)	C18—O8	1.420 (4)
C8—O3	1.418 (4)	C18—H18A	0.9600
C8—H8A	0.9600	C18—H18B	0.9600
C8—H8B	0.9600	C18—H18C	0.9600
C8—H8C	0.9600	C19—O9	1.426 (4)
C9—O4	1.417 (4)	C19—H19A	0.9600
C9—H9A	0.9600	C19—H19B	0.9600
C9—H9B	0.9600	C19—H19C	0.9600
C9—H9C	0.9600	C20—O10	1.422 (5)
C10—O5	1.413 (4)	C20—H20A	0.9600
C10—H10A	0.9600	C20—H20B	0.9600
C10—H10B	0.9600	C20—H20C	0.9600
C10—H10C	0.9600	O2—H2	0.8200
C11—O7	1.255 (3)	O6—H6	0.96 (2)

C1—O2—H2	109.5	H10A—C10—H10B	109.5
C4—O3—C8	117.4 (3)	O5—C10—H10C	109.5
C5—O4—C9	114.9 (2)	H10A—C10—H10C	109.5
C6—O5—C10	117.5 (2)	H10B—C10—H10C	109.5
C11—O6—H6	111 (3)	O7—C11—O6	123.1 (3)
C14—O8—C18	117.9 (2)	O7—C11—C12	118.9 (3)
C15—O9—C19	116.2 (2)	O6—C11—C12	118.0 (3)
C16—O10—C20	117.5 (2)	C17—C12—C13	121.9 (2)
O1—C1—O2	123.1 (3)	C17—C12—C11	118.7 (2)
O1—C1—C2	119.8 (3)	C13—C12—C11	119.4 (3)
O2—C1—C2	117.0 (3)	C12—C13—C14	118.9 (3)
C3—C2—C7	121.4 (2)	C12—C13—H13	120.6
C3—C2—C1	118.9 (3)	C14—C13—H13	120.6
C7—C2—C1	119.7 (3)	O8—C14—C13	124.5 (3)
C2—C3—C4	119.5 (3)	O8—C14—C15	115.4 (2)
C2—C3—H3	120.3	C13—C14—C15	120.0 (2)
C4—C3—H3	120.3	O9—C15—C16	121.1 (3)
O3—C4—C5	116.1 (3)	O9—C15—C14	118.9 (3)
O3—C4—C3	124.2 (3)	C16—C15—C14	119.7 (2)
C5—C4—C3	119.6 (3)	O10—C16—C17	124.1 (3)
O4—C5—C4	120.3 (3)	O10—C16—C15	115.8 (2)
O4—C5—C6	119.2 (3)	C17—C16—C15	120.1 (3)
C4—C5—C6	120.4 (3)	C12—C17—C16	119.4 (3)
O5—C6—C7	123.9 (3)	C12—C17—H17	120.3
O5—C6—C5	116.0 (2)	C16—C17—H17	120.3
C7—C6—C5	120.0 (3)	O8—C18—H18A	109.5
C6—C7—C2	119.0 (3)	O8—C18—H18B	109.5
C6—C7—H7	120.7 (17)	H18A—C18—H18B	109.5
C2—C7—H7	119.9 (17)	O8—C18—H18C	109.5
O3—C8—H8A	109.5	H18A—C18—H18C	109.5
O3—C8—H8B	109.5	H18B—C18—H18C	109.5
H8A—C8—H8B	109.5	O9—C19—H19A	109.5
O3—C8—H8C	109.5	O9—C19—H19B	109.5
H8A—C8—H8C	109.5	H19A—C19—H19B	109.5
H8B—C8—H8C	109.5	O9—C19—H19C	109.5
O4—C9—H9A	109.5	H19A—C19—H19C	109.5
O4—C9—H9B	109.5	H19B—C19—H19C	109.5
H9A—C9—H9B	109.5	O10—C20—H20A	109.5
O4—C9—H9C	109.5	O10—C20—H20B	109.5
H9A—C9—H9C	109.5	H20A—C20—H20B	109.5
H9B—C9—H9C	109.5	O10—C20—H20C	109.5
O5—C10—H10A	109.5	H20A—C20—H20C	109.5
O5—C10—H10B	109.5	H20B—C20—H20C	109.5

O1—C1—C2—C3	2.0 (4)	C12—C13—C14—O8	−179.6 (3)
O2—C1—C2—C3	−177.5 (3)	C12—C13—C14—C15	−1.0 (4)
O1—C1—C2—C7	−176.8 (3)	O8—C14—C15—O9	−5.3 (4)
O2—C1—C2—C7	3.6 (4)	C13—C14—C15—O9	176.0 (3)
C7—C2—C3—C4	1.1 (5)	O8—C14—C15—C16	−179.7 (3)
C1—C2—C3—C4	−177.7 (3)	C13—C14—C15—C16	1.5 (5)
C2—C3—C4—O3	179.9 (3)	O9—C15—C16—O10	5.6 (5)
C2—C3—C4—C5	−0.6 (4)	C14—C15—C16—O10	−180.0 (3)
O3—C4—C5—O4	2.1 (4)	O9—C15—C16—C17	−175.2 (3)
C3—C4—C5—O4	−177.4 (3)	C14—C15—C16—C17	−0.9 (5)
O3—C4—C5—C6	179.1 (3)	C13—C12—C17—C16	0.8 (5)
C3—C4—C5—C6	−0.5 (5)	C11—C12—C17—C16	−177.5 (3)
O4—C5—C6—O5	−2.0 (4)	O10—C16—C17—C12	178.8 (3)
C4—C5—C6—O5	−178.9 (3)	C15—C16—C17—C12	−0.3 (5)
O4—C5—C6—C7	178.0 (3)	C5—C4—O3—C8	−173.1 (3)
C4—C5—C6—C7	1.0 (5)	C3—C4—O3—C8	6.4 (4)
O5—C6—C7—C2	179.5 (3)	C4—C5—O4—C9	−76.3 (4)
C5—C6—C7—C2	−0.5 (5)	C6—C5—O4—C9	106.8 (4)
C3—C2—C7—C6	−0.6 (5)	C7—C6—O5—C10	−12.0 (5)
C1—C2—C7—C6	178.2 (3)	C5—C6—O5—C10	168.0 (3)
O7—C11—C12—C17	−5.4 (4)	C13—C14—O8—C18	−0.9 (4)
O6—C11—C12—C17	173.4 (3)	C15—C14—O8—C18	−179.6 (3)
O7—C11—C12—C13	176.3 (3)	C16—C15—O9—C19	−73.3 (4)
O6—C11—C12—C13	−5.0 (4)	C14—C15—O9—C19	112.3 (4)
C17—C12—C13—C14	−0.2 (4)	C17—C16—O10—C20	2.0 (5)
C11—C12—C13—C14	178.1 (3)	C15—C16—O10—C20	−178.9 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C9—H9C···O7ⁱ	0.96	2.49	3.405 (4)	159
C18—H18A···O5ⁱⁱ	0.96	2.51	3.321 (4)	142
C19—H19C···O1ⁱⁱⁱ	0.96	2.50	3.404 (5)	158
O2—H2···O7^iv	0.82	1.83	2.641 (3)	172
O6—H6···O1^v	0.96 (2)	1.71 (2)	2.656 (3)	170 (5)

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

Experimental details

Crystal data
Chemical formula	C₁₀H₁₂O₅
M_r	212.20
Crystal system, space group	Monoclinic, Pc
Temperature (K)	298
a, b, c (Å)	7.3384 (3), 8.8325 (3), 15.7560 (5)
β (°)	96.576 (2)
V (Å³)	1014.53 (6)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.11
Crystal size (mm)	0.25 × 0.15 × 0.13

Data collection
Diffractometer	Bruker APEXII area-detector
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.935, 0.984
No. of measured, independent and observed [I > 2σ(I)] reflections	7599, 2510, 1563
R_int	0.032
(sin θ/λ)_max (Å⁻¹)	0.667

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.039, 0.094, 1.06
No. of reflections	2510
No. of parameters	281
No. of restraints	3
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.18, −0.17

Computer programs: APEX2 (Bruker, 2005), APEX2, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Selected bond lengths (Å) top

C1—O1	1.243 (4)	C11—O7	1.255 (3)
C1—O2	1.279 (4)	C11—O6	1.269 (3)