Diethyl 2,3-dihydro­thieno[3,4-b]-1,4-dioxine-5,7-dicarboxyl­ate

Ono, K.; Tomura, M.; Saito, K.

doi:10.1107/S1600536808000937

Diethyl 2,3-dihydrothieno[3,4-b]-1,4-dioxine-5,7-dicarboxylate

The title compound, C₁₂H₁₄O₆S, is a dicarboxylic acid diethyl ester of 3,4-ethylenedioxythiophene, which is a component of electrically conductive poly(3,4-ethylenedioxythiophene) (PEDOT). The ethylene group is disordered over two sites with occupancy factors 0.64 and 0.36. Both the carbonyl groups are coplanar with the thiophene ring. The molecules form centrosymmetric dimers with an R₂²(12) coupling by intermolecular C—H

O hydrogen bonds [3.333 (5) Å] at the ethoxycarbonyl groups. The dimer units are arranged to form a ribbon-like molecular sheet.

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536808000937/hg2368sup1.cif Contains datablocks global, I
	Structure factor file (CIF format) https://doi.org/10.1107/S1600536808000937/hg2368Isup2.hkl Contains datablock I

CCDC reference: 677609

checkCIF report

Key indicators

Single-crystal X-ray study
T = 295 K
Mean (C-C) = 0.004 Å
Disorder in main residue
R factor = 0.070
wR factor = 0.177
Data-to-parameter ratio = 15.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.98
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.10
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       2.68 Ratio
PLAT301_ALERT_3_C Main Residue  Disorder .........................      10.00 Perc.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H9B    ..  O3      ..       2.66 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H9A    ..  O3      ..       2.62 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H6B1   ..  O5      ..       2.68 Ang.
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........          8
PLAT779_ALERT_2_C Suspect or Irrelevant (Bond) Angle in CIF ......      33.10 Deg.
              C5B  -O1   -C5A     1.555   1.555   1.555
PLAT779_ALERT_2_C Suspect or Irrelevant (Bond) Angle in CIF ......      28.40 Deg.
              C6B  -O2   -C6A     1.555   1.555   1.555

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

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

Comment top

The title compound (I) has been prepared as a precursor of 3,4-ethylenedioxythiophene (Coffey et al., 1996; Kumar et al., 1998; Zong et al., 2002; Caras-Quintero & Bäuerle, 2002), which is polymerized by oxidizing agents to afford poly(3,4-ethylenedioxythiophene) (PEDOT). PEDOT shows high electrical conductivities and high stabilities in the oxidized states. Furthermore, the thin films of oxidized PEDOT are almost transparent. Therefore, these are used for organic electrodes in the study of electronic devices (Groenendaal et al., 2000; Pei et al., 1994). With regard to the hole-transporting abilities, the arrangement of 3,4-ethylenedioxythiophene units in film has attracted considerable attention. A few crystal structures including a 3,4-ethylenedioxythiophene ring system were reported (Sotzing et al., 1996; Abboud et al., 1998; Kumar et al., 1998). In this paper, we report the crystal structure of compound (I) that is a dicarboxylic acid diethyl ester of 3,4-ethylenedioxythiophene.

The compound (I) crystallizes in the P1 space group. The molecular structure is shown in Fig. 1. The ethylene moiety is disordered over two sites (O1—C5A—C6A—O2 and O1—C5B—C6B—O2) with occupancies of 0.36:0.64. The bond lengths and angles are all within expected ranges (Allen et al., 1987). Both the carbonyl moieties are planar to the thiophene ring. The molecules form a centrosymmetric dimer with a graph-set motif (Bernstein et al., 1995) of R₂²(12) by intermolecular C–H···O hydrogen bonds at the ethoxycarbonyl groups [C9–H9B···O3(–x + 3, –y, –z): 3.333 (5) Å]. The dimer units are arranged to form a ribbon-like molecular sheet along the b axis, as shown in Fig. 2. The ribbon-like molecular sheets stack to form a layer structure (Fig. 3).

Related literature top

The title compound was synthesized as a precursor of 3,4-ethylenedioxythiophene, which is polymerized to afford PEDOT (Groenendaal et al., 2000; Pei et al., 1994). Synthetic methods for the title compound have been reported by: Coffey et al. (1996); Kumar et al. (1998); Zong et al. (2002); Caras-Quintero & Bäuerle (2002). For literature on related molecular structures, including a 3,4-ethylenedioxythiophene ring system, see: Sotzing et al. (1996); Abboud et al. (1998); Kumar et al. (1998). For related literature, see: Bernstein et al. (1995); Allen et al. (1987); Pei et al. (1994).

Experimental top

The title compound (I) was prepared as follows: A solution of diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate (3.12 g, 12 mmol) and caesium fluoride (7.26 g, 48 mmol) in dry acetonitrile (200 ml) was stirred for 1 h under nitrogen. After addition of a solution of ethylene di(p-toluenesulfonate) (5.55 g, 15 mmol) in dry acetonitrile (100 ml), the reaction mixture was refluxed for 48 h. The reaction mixture was filtered and the precipitate was washed with acetonitrile. The filtrate was concentrated and the residue was chromatographed on alumina gel (CH₂Cl₂) and silica gel (CH₂Cl₂) to afford the compound of (I) (2.38 g, 69%) as colorless needles. Physical data for (I): m.p. 424–425 K; IR (KBr, cm^-1) 2998, 1698, 1454, 1377, 1302, 1098; ¹H NMR (CDCl₃, δ p.p.m): 1.37 (t, J = 7.1 Hz, 6H), 4.35 (q, J = 7.1 Hz, 4H), 4.40 (s, 4H); ¹³C NMR (CDCl₃, δ p.p.m): 14.2, 61.3, 64.7, 111.8, 144.9, 160.7; MS (EI): m/z 286 (M⁺), 241, 213, 169. Anal. Calcd for C₁₂H₁₄O₆S: C, 50.34; H, 4.93. Found: C, 50.50; H, 4.96. Colorless crystals of (I) suitable for X-ray analysis were obtained from a methanol solution.

Computing details top

Data collection: CrystalClear (Rigaku/MSC, 2001); cell refinement: CrystalClear (Rigaku/MSC, 2001); data reduction: CrystalClear (Rigaku/MSC, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2003) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of (I), with atom labels and 50% probability displacement ellipsoids for non-H atoms and H atoms are shown as small spheres of arbitrary radii. The disordered atoms (C5B and C6B) are omitted for clarity.
	Fig. 2. The packing diagram of (I), ribbon-like molecular sheet.
	Fig. 3. The packing diagram of (I), packing mode of molecular sheets.

Diethyl 2,3-dihydrothieno[3,4-b]-1,4-dioxine-5,7-dicarboxylate top

Crystal data top

C₁₂H₁₄O₆S	Z = 2
M_r = 286.30	F(000) = 300
Triclinic, P1	D_x = 1.460 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71070 Å
a = 4.6805 (8) Å	Cell parameters from 1654 reflections
b = 8.3673 (17) Å	θ = 3.3–27.5°
c = 17.351 (3) Å	µ = 0.27 mm⁻¹
α = 94.294 (7)°	T = 295 K
β = 92.024 (9)°	Plate, colorless
γ = 105.641 (9)°	0.60 × 0.10 × 0.08 mm
V = 651.4 (2) Å³

Data collection top

Rigaku/MSC Mercury CCD diffractometer	2300 reflections with I > 2σ(I)
Radiation source: Rotating Anode	R_int = 0.036
Graphite Monochromator monochromator	θ_max = 27.5°, θ_min = 3.3°
Detector resolution: 14.6199 pixels mm^-1	h = −4→6
ϕ and ω scans	k = −10→10
5181 measured reflections	l = −22→19
2899 independent reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.069	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.176	H-atom parameters constrained
S = 1.11	w = 1/[σ²(F_o²) + (0.0793P)² + 0.337P] where P = (F_o² + 2F_c²)/3
2899 reflections	(Δ/σ)_max < 0.001
193 parameters	Δρ_max = 0.55 e Å⁻³
0 restraints	Δρ_min = −0.26 e Å⁻³

Crystal data top

C₁₂H₁₄O₆S	γ = 105.641 (9)°
M_r = 286.30	V = 651.4 (2) Å³
Triclinic, P1	Z = 2
a = 4.6805 (8) Å	Mo Kα radiation
b = 8.3673 (17) Å	µ = 0.27 mm⁻¹
c = 17.351 (3) Å	T = 295 K
α = 94.294 (7)°	0.60 × 0.10 × 0.08 mm
β = 92.024 (9)°

Data collection top

Rigaku/MSC Mercury CCD diffractometer	2300 reflections with I > 2σ(I)
5181 measured reflections	R_int = 0.036
2899 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.069	0 restraints
wR(F²) = 0.176	H-atom parameters constrained
S = 1.11	Δρ_max = 0.55 e Å⁻³
2899 reflections	Δρ_min = −0.26 e Å⁻³
193 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.

The methylene carbon atoms and the associated hydrogen atoms of the dioxine ring are disordered over two sites (O1—C5A—C6A—O2 and O1—C5B—C6B—O2) with occupancies of 0.36 (2):0.64 (2). The values were determined by refining site occupancies.

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
S1	0.86744 (17)	0.05411 (9)	0.23931 (5)	0.0487 (3)
O1	1.1659 (5)	0.5120 (3)	0.18957 (13)	0.0547 (6)
O2	0.7713 (5)	0.4829 (2)	0.31477 (12)	0.0501 (5)
O3	1.2360 (6)	0.0234 (3)	0.11029 (18)	0.0783 (8)
O4	1.4165 (6)	0.2967 (3)	0.09719 (14)	0.0649 (7)
O5	0.4735 (5)	−0.0297 (3)	0.36729 (15)	0.0632 (6)
O6	0.4318 (4)	0.2289 (3)	0.39704 (12)	0.0491 (5)
C1	1.0739 (6)	0.2137 (4)	0.19066 (17)	0.0430 (6)
C2	1.0364 (6)	0.3648 (3)	0.21764 (16)	0.0400 (6)
C3	0.8393 (6)	0.3508 (3)	0.27903 (15)	0.0377 (6)
C4	0.7311 (6)	0.1889 (3)	0.29702 (16)	0.0399 (6)
C5A	1.162 (5)	0.6525 (14)	0.2449 (14)	0.062 (5)	0.36 (2)
H5A1	1.2257	0.7562	0.2207	0.074*	0.36 (2)
H5A2	1.2966	0.6576	0.2893	0.074*	0.36 (2)
C6A	0.855 (5)	0.629 (2)	0.2697 (13)	0.059 (4)	0.36 (2)
H6A1	0.8417	0.7271	0.3011	0.070*	0.36 (2)
H6A2	0.7183	0.6125	0.2246	0.070*	0.36 (2)
C5B	1.018 (4)	0.6382 (11)	0.2131 (7)	0.065 (3)	0.64 (2)
H5B1	0.8276	0.6153	0.1843	0.078*	0.64 (2)
H5B2	1.1379	0.7469	0.2017	0.078*	0.64 (2)
C6B	0.971 (4)	0.6381 (10)	0.2987 (7)	0.063 (3)	0.64 (2)
H6B1	1.1603	0.6543	0.3272	0.076*	0.64 (2)
H6B2	0.8898	0.7292	0.3153	0.076*	0.64 (2)
C7	1.2491 (7)	0.1675 (4)	0.12851 (19)	0.0517 (7)
C8	1.5944 (10)	0.2624 (6)	0.0335 (2)	0.0806 (12)
H8A	1.7836	0.3470	0.0367	0.097*
H8B	1.6335	0.1552	0.0378	0.097*
C9	1.4402 (13)	0.2613 (7)	−0.0398 (3)	0.1016 (16)
H9A	1.2575	0.1739	−0.0439	0.152*
H9B	1.5623	0.2426	−0.0809	0.152*
H9C	1.3978	0.3666	−0.0435	0.152*
C10	0.5316 (6)	0.1166 (3)	0.35600 (17)	0.0444 (6)
C11	0.2365 (7)	0.1649 (4)	0.45733 (19)	0.0571 (8)
H11A	0.3405	0.1178	0.4951	0.069*
H11B	0.0649	0.0783	0.4352	0.069*
C12	0.1406 (9)	0.3054 (5)	0.4950 (2)	0.0747 (11)
H12A	0.3081	0.3833	0.5227	0.112*
H12B	−0.0094	0.2637	0.5303	0.112*
H12C	0.0612	0.3602	0.4562	0.112*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1	0.0565 (5)	0.0320 (4)	0.0588 (5)	0.0137 (3)	0.0039 (3)	0.0041 (3)
O1	0.0743 (14)	0.0356 (11)	0.0540 (13)	0.0104 (10)	0.0276 (10)	0.0088 (9)
O2	0.0703 (13)	0.0307 (10)	0.0490 (12)	0.0103 (9)	0.0232 (10)	0.0043 (8)
O3	0.0888 (18)	0.0575 (15)	0.095 (2)	0.0335 (14)	0.0233 (15)	−0.0121 (14)
O4	0.0793 (16)	0.0678 (16)	0.0562 (14)	0.0309 (13)	0.0280 (12)	0.0075 (12)
O5	0.0707 (14)	0.0373 (12)	0.0790 (17)	0.0050 (10)	0.0115 (12)	0.0213 (11)
O6	0.0515 (11)	0.0418 (11)	0.0513 (12)	0.0041 (9)	0.0154 (9)	0.0127 (9)
C1	0.0454 (15)	0.0401 (15)	0.0445 (16)	0.0144 (12)	0.0023 (12)	0.0004 (12)
C2	0.0462 (14)	0.0328 (13)	0.0396 (14)	0.0079 (11)	0.0048 (11)	0.0039 (11)
C3	0.0421 (13)	0.0317 (13)	0.0379 (14)	0.0079 (10)	0.0030 (10)	0.0028 (11)
C4	0.0429 (14)	0.0313 (13)	0.0444 (15)	0.0080 (11)	0.0017 (11)	0.0049 (11)
C5A	0.089 (10)	0.021 (4)	0.066 (9)	0.000 (5)	0.024 (7)	−0.007 (5)
C6A	0.089 (11)	0.029 (5)	0.059 (10)	0.016 (6)	0.017 (7)	0.004 (6)
C5B	0.109 (8)	0.036 (3)	0.056 (5)	0.023 (4)	0.038 (5)	0.013 (3)
C6B	0.100 (7)	0.026 (3)	0.055 (5)	0.002 (4)	0.036 (4)	0.004 (3)
C7	0.0530 (17)	0.0508 (18)	0.0554 (18)	0.0238 (14)	0.0030 (14)	−0.0049 (15)
C8	0.082 (3)	0.106 (3)	0.068 (3)	0.047 (2)	0.028 (2)	0.005 (2)
C9	0.154 (5)	0.099 (4)	0.071 (3)	0.066 (3)	0.027 (3)	0.006 (3)
C10	0.0441 (14)	0.0361 (14)	0.0488 (16)	0.0014 (11)	0.0009 (12)	0.0122 (12)
C11	0.0505 (17)	0.064 (2)	0.0530 (19)	0.0031 (15)	0.0139 (14)	0.0208 (16)
C12	0.073 (2)	0.079 (3)	0.062 (2)	0.003 (2)	0.0216 (18)	0.000 (2)

Geometric parameters (Å, º) top

S1—C4	1.716 (3)	C5A—H5A2	0.9700
S1—C1	1.720 (3)	C6A—H6A1	0.9700
O1—C2	1.352 (3)	C6A—H6A2	0.9700
O1—C5B	1.453 (8)	C5B—C6B	1.508 (18)
O1—C5A	1.466 (13)	C5B—H5B1	0.9700
O2—C3	1.345 (3)	C5B—H5B2	0.9700
O2—C6B	1.435 (9)	C6B—H6B1	0.9700
O2—C6A	1.468 (16)	C6B—H6B2	0.9700
O3—C7	1.207 (4)	C8—C9	1.439 (6)
O4—C7	1.319 (4)	C8—H8A	0.9700
O4—C8	1.463 (4)	C8—H8B	0.9700
O5—C10	1.213 (3)	C9—H9A	0.9600
O6—C10	1.329 (4)	C9—H9B	0.9600
O6—C11	1.451 (3)	C9—H9C	0.9600
C1—C2	1.373 (4)	C11—C12	1.483 (5)
C1—C7	1.468 (4)	C11—H11A	0.9700
C2—C3	1.425 (4)	C11—H11B	0.9700
C3—C4	1.376 (4)	C12—H12A	0.9600
C4—C10	1.463 (4)	C12—H12B	0.9600
C5A—C6A	1.48 (3)	C12—H12C	0.9600
C5A—H5A1	0.9700

C4—S1—C1	91.98 (13)	H5B1—C5B—H5B2	108.2
C2—O1—C5B	111.5 (4)	O2—C6B—C5B	110.0 (11)
C2—O1—C5A	111.2 (6)	O2—C6B—H6B1	109.7
C5B—O1—C5A	33.1 (6)	C5B—C6B—H6B1	109.7
C3—O2—C6B	112.4 (4)	O2—C6B—H6B2	109.7
C3—O2—C6A	111.3 (7)	C5B—C6B—H6B2	109.7
C6B—O2—C6A	28.4 (6)	H6B1—C6B—H6B2	108.2
C7—O4—C8	117.3 (3)	O3—C7—O4	125.4 (3)
C10—O6—C11	115.5 (2)	O3—C7—C1	121.2 (3)
C2—C1—C7	131.7 (3)	O4—C7—C1	113.4 (3)
C2—C1—S1	111.6 (2)	C9—C8—O4	110.4 (3)
C7—C1—S1	116.7 (2)	C9—C8—H8A	109.6
O1—C2—C1	125.0 (3)	O4—C8—H8A	109.6
O1—C2—C3	122.6 (2)	C9—C8—H8B	109.6
C1—C2—C3	112.4 (2)	O4—C8—H8B	109.6
O2—C3—C4	124.8 (2)	H8A—C8—H8B	108.1
O2—C3—C2	122.8 (2)	C8—C9—H9A	109.5
C4—C3—C2	112.4 (2)	C8—C9—H9B	109.5
C3—C4—C10	131.5 (3)	H9A—C9—H9B	109.5
C3—C4—S1	111.6 (2)	C8—C9—H9C	109.5
C10—C4—S1	116.8 (2)	H9A—C9—H9C	109.5
O1—C5A—C6A	108.4 (18)	H9B—C9—H9C	109.5
O1—C5A—H5A1	110.0	O5—C10—O6	124.2 (3)
C6A—C5A—H5A1	110.0	O5—C10—C4	122.8 (3)
O1—C5A—H5A2	110.0	O6—C10—C4	112.9 (2)
C6A—C5A—H5A2	110.0	O6—C11—C12	107.9 (3)
H5A1—C5A—H5A2	108.4	O6—C11—H11A	110.1
O2—C6A—C5A	110.1 (18)	C12—C11—H11A	110.1
O2—C6A—H6A1	109.6	O6—C11—H11B	110.1
C5A—C6A—H6A1	109.6	C12—C11—H11B	110.1
O2—C6A—H6A2	109.6	H11A—C11—H11B	108.4
C5A—C6A—H6A2	109.6	C11—C12—H12A	109.5
H6A1—C6A—H6A2	108.2	C11—C12—H12B	109.5
O1—C5B—C6B	109.7 (11)	H12A—C12—H12B	109.5
O1—C5B—H5B1	109.7	C11—C12—H12C	109.5
C6B—C5B—H5B1	109.7	H12A—C12—H12C	109.5
O1—C5B—H5B2	109.7	H12B—C12—H12C	109.5
C6B—C5B—H5B2	109.7

C4—S1—C1—C2	−0.5 (2)	C2—O1—C5A—C6A	−50 (3)
C4—S1—C1—C7	−179.3 (2)	C5B—O1—C5A—C6A	46.7 (17)
C5B—O1—C2—C1	162.8 (8)	C3—O2—C6A—C5A	−48 (2)
C5A—O1—C2—C1	−161.5 (13)	C6B—O2—C6A—C5A	50 (2)
C5B—O1—C2—C3	−16.3 (9)	O1—C5A—C6A—O2	67 (3)
C5A—O1—C2—C3	19.4 (13)	C2—O1—C5B—C6B	47.5 (16)
C7—C1—C2—O1	−0.2 (5)	C5A—O1—C5B—C6B	−48.7 (13)
S1—C1—C2—O1	−178.7 (2)	C3—O2—C6B—C5B	46.3 (17)
C7—C1—C2—C3	179.0 (3)	C6A—O2—C6B—C5B	−47.3 (18)
S1—C1—C2—C3	0.5 (3)	O1—C5B—C6B—O2	−65 (2)
C6B—O2—C3—C4	164.7 (8)	C8—O4—C7—O3	1.9 (5)
C6A—O2—C3—C4	−164.7 (11)	C8—O4—C7—C1	−178.7 (3)
C6B—O2—C3—C2	−14.9 (9)	C2—C1—C7—O3	−174.9 (3)
C6A—O2—C3—C2	15.7 (11)	S1—C1—C7—O3	3.5 (4)
O1—C2—C3—O2	−1.3 (4)	C2—C1—C7—O4	5.7 (5)
C1—C2—C3—O2	179.5 (2)	S1—C1—C7—O4	−175.8 (2)
O1—C2—C3—C4	179.0 (3)	C7—O4—C8—C9	95.4 (4)
C1—C2—C3—C4	−0.2 (4)	C11—O6—C10—O5	−1.4 (4)
O2—C3—C4—C10	−1.2 (5)	C11—O6—C10—C4	−179.1 (2)
C2—C3—C4—C10	178.4 (3)	C3—C4—C10—O5	−175.0 (3)
O2—C3—C4—S1	−179.9 (2)	S1—C4—C10—O5	3.6 (4)
C2—C3—C4—S1	−0.2 (3)	C3—C4—C10—O6	2.7 (5)
C1—S1—C4—C3	0.4 (2)	S1—C4—C10—O6	−178.76 (18)
C1—S1—C4—C10	−178.4 (2)	C10—O6—C11—C12	−178.2 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C9—H9B···O3ⁱ	0.96	2.66	3.333 (5)	127
C9—H9A···O3ⁱⁱ	0.96	2.62	3.523 (7)	157
C6B—H6B1···O5ⁱⁱⁱ	0.97	2.68	3.233 (12)	117

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

Experimental details

Crystal data
Chemical formula	C₁₂H₁₄O₆S
M_r	286.30
Crystal system, space group	Triclinic, P1
Temperature (K)	295
a, b, c (Å)	4.6805 (8), 8.3673 (17), 17.351 (3)
α, β, γ (°)	94.294 (7), 92.024 (9), 105.641 (9)
V (Å³)	651.4 (2)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.27
Crystal size (mm)	0.60 × 0.10 × 0.08

Data collection
Diffractometer	Rigaku/MSC Mercury CCD diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	5181, 2899, 2300
R_int	0.036
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.069, 0.176, 1.11
No. of reflections	2899
No. of parameters	193
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.55, −0.26

Computer programs: CrystalClear (Rigaku/MSC, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2003) and Mercury (Macrae et al., 2006).