(E)-4-(β-d-Allopyran­os­yloxy)cinnamyl 4-bromo­phenyl ketone ethanol solvate

Yin, X.-J.; Bai, X.; Zheng, L.; Li, Y.; Yin, S.-F.

doi:10.1107/S1600536809029687

organic compounds

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ISSN: 2056-9890

Volume 65| Part 8| August 2009| Page o2044

doi:10.1107/S1600536809029687

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(E)-4-(β-D-Allopyranosyloxy)cinnamyl 4-bromophenyl ketone ethanol solvate

Xiu-Juan Yin,^a Xue Bai,^a Lei Zheng,^a Ying Li ^a and Shu-Fan Yin ^a ^*

^aCollege of Chemistry, Sichuan University, Chengdu 610064, People's Republic of China
^*Correspondence e-mail: chuandayouji217@163.com

(Received 15 July 2009; accepted 25 July 2009; online 31 July 2009)

The title compound, C₂₁H₂₁BrO₇·C₂H₆O, was synthesized by the Claisen–Schimidt reaction of helicid (systematic name: 4-formylphenyl-β-D-allopyranoside) with 4-bromoacetophenone in ethanol. The pyran ring adopts a chair conformation. In the crystal structure, molecules are linked into a three-dimensional network by intermolecular O—H⋯O hydrogen bonds.

Related literature

For helicid and its biological activity, see: Chen et al. (1981 ); Sha & Mao (1987 ). For the synthesis and structure of related compound, see: Fan et al. (2007 ); Fu et al. (2009 ); Lv et al. (2009 ); Yang et al. (2009 ); Ye et al. (2009 ).

Experimental

Crystal data

C₂₁H₂₁BrO₇·C₂H₆O
M_r = 511.36
Monoclinic, P 2₁
a = 10.977 (2) Å
b = 7.6518 (15) Å
c = 13.259 (3) Å
β = 92.08 (3)°
V = 1113.0 (4) Å³
Z = 2
Mo Kα radiation
μ = 1.89 mm⁻¹
T = 113 K
0.20 × 0.16 × 0.12 mm

Data collection

Rigaku Saturn CCD area-detector diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005 ) T_min = 0.703, T_max = 0.805
9199 measured reflections
5171 independent reflections
3636 reflections with I > 2σ(I)
R_int = 0.039

Refinement

R[F² > 2σ(F²)] = 0.032
wR(F²) = 0.056
S = 0.75
5171 reflections
296 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.67 e Å⁻³
Δρ_min = −0.39 e Å⁻³
Absolute structure: Flack (1983 ), 2358 Friedel pairs
Flack parameter: 0.027 (6)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯O3ⁱ	0.84	1.97	2.783 (3)	164
O3—H3⋯O7ⁱⁱ	0.84	2.05	2.702 (3)	134
O3—H3⋯O4	0.84	2.38	2.786 (3)	110
O4—H4⋯O2ⁱⁱⁱ	0.84	1.85	2.677 (3)	166
O5—H5⋯O8^iv	0.84	1.91	2.678 (3)	152
O8—H8A⋯O1^iv	0.84	2.08	2.893 (3)	163
Symmetry codes: (i) $[-x, y-{\script{1\over 2}}, -z-1]$ ; (ii) $[-x, y+{\script{1\over 2}}, -z]$ ; (iii) x, y+1, z; (iv) $[-x+1, y+{\script{1\over 2}}, -z]$ .

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.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809029687/rz2355sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809029687/rz2355Isup2.hkl

checkCIF report

Comment top

Helicid (systematic name: 4-formylphenyl-β-D-allopyranoside; Chen et al. 1981), is a pure natural compound extracted from the fruit of Helicia Nilagirica Beed, which has been successfully used in the treatment of insomnia in China. Some helicid derivatives have been reported to possess good biological activities (Sha & Mao, 1987). The synthesis and structure of some helicid derivatives heve been recently reported by our group (Fu et al. 2009; Lv et al. 2009; Yang et al. 2009; Ye et al. 2009). As a continuation of our studies in this area, we report herein the crystal structure of the title compound.

In the molecule of the title compound (Fig. 1), the average of C–C, C(sp³)–O and C(sp²)–O bond lengths in the pyranoside unit are 1.524 (4), 1.421 (4) and 1.241 (3) Å, respectively. The pyran ring adopts chair conformation with the hydroxy group at C4 in axial position and the other substituents at C2, C3 and C5 in equatorial positions. The O1–C2–C3–O3 and O2–C1–C2–O1 torsion angles are -176.5 (2) ° and -59.0 (3) °, respectively, while the O5–C5–C6–O1 and O7–C15–C16–C21 torsion angles are -173.9 (2) ° and -172.2 (3) °, respectively, possibly as a consequence of the presence of O—H···O hydrogen bonds. In the crystal packing, the molecules are linked by intermolecular O—H···O hydrogen bonds (Table 1) involving the hydroxy groups of the pyranoside unit and the ethanol molecule to form a three-dimensional network.

Related literature top

For helicid and its biological activity, see: Chen et al. (1981); Sha & Mao (1987). For the synthesis and structure of related compound, see: Fan et al. (2007); Fu et al. (2009); Lv et al. (2009); Yang et al. (2009); Ye et al. (2009).

Experimental top

The synthetic method of the title compound was reported elsewhere (Fan et al., 2007). To a solution of helicid (1.420 g, 5 mmol) in 30 ml of anhydrous ethanol, a 10% NaOH aqueous solution were added under ice bath, then 4-bromoacetophenone (1.104 g, 5.5 mmol) was added. The mixture was neutralized with diluted hydrochloric acid, concentrated to half of the original volume, and the resulting precipitate filtered. Colourless single crystals suitable for X-ray analysis were obtained by slow evaporation of an ethanol solution (yield 65%, m.p. 98–100 K).

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

Fig. 1. The molecular structure of the title compound, with displacement ellipsoids drawn at the 30% probability level.

(E)-4-(β-D-Allopyranosyloxy)cinnamyl 4-bromophenyl ketone ethanol solvate top

Crystal data top

C₂₁H₂₁BrO₇·C₂H₆O	F(000) = 528
M_r = 511.36	D_x = 1.526 Mg m⁻³
Monoclinic, P2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 3521 reflections
a = 10.977 (2) Å	θ = 1.5–27.9°
b = 7.6518 (15) Å	µ = 1.89 mm⁻¹
c = 13.259 (3) Å	T = 113 K
β = 92.08 (3)°	Block, colourless
V = 1113.0 (4) Å³	0.20 × 0.16 × 0.12 mm
Z = 2

Data collection top

Rigaku Saturn CCD area-detector diffractometer	5171 independent reflections
Radiation source: rotating anode	3636 reflections with I > 2σ(I)
Confocal monochromator	R_int = 0.039
Detector resolution: 7.31 pixels mm^-1	θ_max = 27.9°, θ_min = 1.5°
ω and ϕ scans	h = −14→14
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005)	k = −10→10
T_min = 0.703, T_max = 0.805	l = −13→17
9199 measured reflections

Refinement top

Refinement on F²	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F² > 2σ(F²)] = 0.032	w = 1/[σ²(F_o²)] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.056	(Δ/σ)_max = 0.003
S = 0.75	Δρ_max = 0.67 e Å⁻³
5171 reflections	Δρ_min = −0.39 e Å⁻³
296 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008)
1 restraint	Extinction coefficient: 0.0242 (11)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 2358 Friedel pairs
Secondary atom site location: difference Fourier map	Absolute structure parameter: 0.027 (6)

Crystal data top

C₂₁H₂₁BrO₇·C₂H₆O	V = 1113.0 (4) Å³
M_r = 511.36	Z = 2
Monoclinic, P2₁	Mo Kα radiation
a = 10.977 (2) Å	µ = 1.89 mm⁻¹
b = 7.6518 (15) Å	T = 113 K
c = 13.259 (3) Å	0.20 × 0.16 × 0.12 mm
β = 92.08 (3)°

Data collection top

Rigaku Saturn CCD area-detector diffractometer	5171 independent reflections
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005)	3636 reflections with I > 2σ(I)
T_min = 0.703, T_max = 0.805	R_int = 0.039
9199 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.032	H-atom parameters constrained
wR(F²) = 0.056	Δρ_max = 0.67 e Å⁻³
S = 0.75	Δρ_min = −0.39 e Å⁻³
5171 reflections	Absolute structure: Flack (1983), 2358 Friedel pairs
296 parameters	Absolute structure parameter: 0.027 (6)
1 restraint

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
Br1	0.70240 (2)	0.31136 (4)	0.80385 (2)	0.02313 (10)
O1	0.15927 (15)	0.3593 (2)	−0.22799 (13)	0.0125 (5)
O2	0.08102 (18)	0.0860 (3)	−0.35522 (15)	0.0166 (5)
H2	0.0553	0.0678	−0.4147	0.025*
O3	−0.04022 (16)	0.4996 (3)	−0.44247 (14)	0.0162 (5)
H3	−0.0788	0.5823	−0.4169	0.024*
O4	0.05197 (19)	0.7491 (2)	−0.30705 (18)	0.0153 (5)
H4	0.0691	0.8554	−0.3136	0.023*
O5	0.32128 (15)	0.7681 (2)	−0.28189 (15)	0.0164 (5)
H5	0.2777	0.8430	−0.2541	0.025*
O6	0.32452 (16)	0.4805 (3)	−0.14705 (14)	0.0143 (5)
O7	0.23659 (17)	0.2120 (3)	0.45816 (14)	0.0192 (5)
C1	−0.0025 (3)	0.1941 (4)	−0.3055 (2)	0.0168 (8)
H1A	−0.0209	0.1412	−0.2396	0.020*
H1B	−0.0796	0.2006	−0.3464	0.020*
C2	0.0466 (2)	0.3767 (4)	−0.2884 (2)	0.0122 (7)
H2A	−0.0134	0.4455	−0.2496	0.015*
C3	0.0726 (3)	0.4741 (4)	−0.3866 (2)	0.0108 (7)
H3A	0.1279	0.4012	−0.4276	0.013*
C4	0.1343 (3)	0.6463 (4)	−0.3622 (2)	0.0142 (7)
H4A	0.1532	0.7077	−0.4264	0.017*
C5	0.2521 (2)	0.6144 (4)	−0.3006 (2)	0.0127 (7)
H5A	0.3033	0.5322	−0.3396	0.015*
C6	0.2173 (2)	0.5219 (4)	−0.2039 (2)	0.0126 (7)
H6	0.1627	0.5976	−0.1639	0.015*
C7	0.3110 (3)	0.4342 (4)	−0.0469 (2)	0.0135 (7)
C8	0.1998 (2)	0.4166 (4)	−0.0018 (2)	0.0145 (7)
H8	0.1258	0.4363	−0.0394	0.017*
C9	0.1983 (2)	0.3697 (4)	0.0992 (2)	0.0156 (7)
H9	0.1221	0.3584	0.1303	0.019*
C10	0.3045 (2)	0.3390 (4)	0.1562 (2)	0.0136 (7)
C11	0.4158 (2)	0.3544 (4)	0.1087 (2)	0.0190 (8)
H11	0.4899	0.3316	0.1457	0.023*
C12	0.4188 (2)	0.4030 (4)	0.0076 (2)	0.0178 (7)
H12	0.4947	0.4147	−0.0240	0.021*
C13	0.2936 (2)	0.2962 (5)	0.26334 (19)	0.0167 (7)
H13	0.2127	0.2824	0.2851	0.020*
C14	0.3805 (2)	0.2741 (4)	0.3339 (2)	0.0141 (7)
H14	0.4640	0.2796	0.3177	0.017*
C15	0.3446 (3)	0.2406 (4)	0.4391 (2)	0.0142 (7)
C16	0.4376 (2)	0.2468 (4)	0.5234 (2)	0.0116 (7)
C17	0.4006 (3)	0.2023 (4)	0.6211 (2)	0.0146 (7)
H17	0.3199	0.1618	0.6302	0.017*
C18	0.4800 (2)	0.2172 (4)	0.7029 (2)	0.0152 (7)
H18	0.4547	0.1872	0.7684	0.018*
C19	0.5973 (2)	0.2762 (4)	0.6893 (2)	0.0150 (8)
C20	0.6379 (2)	0.3148 (5)	0.59468 (18)	0.0139 (6)
H20	0.7194	0.3525	0.5864	0.017*
C21	0.5579 (2)	0.2977 (5)	0.51141 (18)	0.0137 (6)
H21	0.5857	0.3211	0.4457	0.016*
O8	0.7446 (2)	0.5264 (3)	0.15901 (15)	0.0236 (5)
H8A	0.7702	0.6293	0.1661	0.035*
C22	0.7527 (2)	0.4749 (4)	0.0559 (2)	0.0186 (7)
H22A	0.7139	0.5652	0.0120	0.022*
H22B	0.7076	0.3642	0.0448	0.022*
C23	0.8844 (2)	0.4500 (4)	0.0265 (2)	0.0283 (9)
H23A	0.9281	0.5612	0.0334	0.042*
H23B	0.8862	0.4100	−0.0437	0.042*
H23C	0.9237	0.3626	0.0708	0.042*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.02318 (17)	0.03083 (19)	0.01506 (14)	−0.0005 (2)	−0.00380 (11)	−0.0020 (2)
O1	0.0135 (10)	0.0100 (12)	0.0137 (10)	−0.0031 (9)	−0.0042 (8)	0.0028 (8)
O2	0.0266 (13)	0.0125 (13)	0.0105 (12)	0.0026 (11)	−0.0005 (10)	−0.0007 (10)
O3	0.0193 (12)	0.0162 (12)	0.0128 (12)	0.0055 (10)	−0.0041 (9)	−0.0025 (10)
O4	0.0169 (11)	0.0075 (11)	0.0216 (12)	0.0025 (9)	0.0040 (9)	−0.0012 (9)
O5	0.0157 (11)	0.0123 (14)	0.0214 (12)	−0.0043 (9)	0.0046 (9)	−0.0034 (9)
O6	0.0117 (11)	0.0202 (13)	0.0108 (11)	−0.0012 (9)	−0.0022 (9)	0.0021 (10)
O7	0.0108 (11)	0.0321 (14)	0.0148 (12)	−0.0053 (10)	0.0011 (9)	−0.0017 (10)
C1	0.020 (2)	0.0157 (18)	0.0144 (17)	0.0003 (15)	0.0014 (15)	0.0018 (15)
C2	0.0133 (17)	0.0116 (16)	0.0118 (16)	−0.0002 (13)	−0.0007 (13)	0.0000 (13)
C3	0.0106 (16)	0.0127 (17)	0.0091 (17)	0.0015 (14)	−0.0009 (13)	0.0010 (14)
C4	0.0166 (18)	0.0129 (17)	0.0135 (17)	0.0049 (14)	0.0071 (14)	0.0010 (14)
C5	0.0142 (16)	0.0104 (17)	0.0135 (16)	−0.0022 (13)	0.0021 (13)	−0.0012 (13)
C6	0.0142 (17)	0.0122 (16)	0.0113 (16)	0.0019 (14)	−0.0012 (13)	−0.0049 (14)
C7	0.0124 (16)	0.0186 (18)	0.0096 (16)	−0.0005 (14)	0.0014 (13)	−0.0024 (14)
C8	0.0102 (16)	0.0181 (18)	0.0148 (17)	0.0019 (14)	−0.0060 (13)	−0.0002 (14)
C9	0.0111 (15)	0.0218 (18)	0.0139 (16)	0.0004 (13)	0.0028 (12)	−0.0018 (13)
C10	0.0123 (14)	0.014 (2)	0.0145 (14)	−0.0020 (15)	−0.0004 (11)	−0.0002 (14)
C11	0.0130 (15)	0.029 (2)	0.0148 (15)	−0.0016 (14)	−0.0026 (12)	0.0016 (14)
C12	0.0090 (16)	0.0261 (19)	0.0185 (17)	−0.0015 (14)	0.0011 (13)	−0.0065 (14)
C13	0.0176 (15)	0.0177 (17)	0.0152 (14)	−0.0017 (19)	0.0037 (11)	−0.0018 (18)
C14	0.0130 (15)	0.014 (2)	0.0159 (15)	−0.0009 (14)	0.0032 (12)	0.0025 (14)
C15	0.0182 (17)	0.0133 (16)	0.0111 (16)	0.0031 (13)	−0.0010 (13)	−0.0029 (13)
C16	0.0161 (16)	0.0104 (15)	0.0084 (15)	0.0018 (13)	0.0003 (12)	−0.0021 (12)
C17	0.0119 (16)	0.0166 (18)	0.0155 (17)	0.0010 (13)	0.0045 (13)	0.0006 (14)
C18	0.0198 (18)	0.0188 (18)	0.0072 (15)	0.0014 (14)	0.0009 (13)	0.0029 (13)
C19	0.0176 (15)	0.013 (2)	0.0136 (14)	0.0049 (14)	−0.0041 (12)	−0.0014 (14)
C20	0.0106 (13)	0.0156 (14)	0.0156 (13)	−0.004 (2)	−0.0002 (10)	0.002 (2)
C21	0.0144 (14)	0.0167 (16)	0.0103 (13)	−0.0015 (19)	0.0045 (10)	0.0022 (18)
O8	0.0384 (14)	0.0154 (13)	0.0172 (13)	−0.0044 (11)	0.0052 (11)	−0.0017 (11)
C22	0.0192 (18)	0.0199 (19)	0.0164 (18)	0.0015 (15)	−0.0031 (14)	−0.0034 (15)
C23	0.0161 (18)	0.037 (2)	0.031 (2)	0.0019 (16)	−0.0027 (15)	−0.0014 (18)

Geometric parameters (Å, º) top

Br1—C19	1.893 (3)	C9—C10	1.385 (3)
O1—C6	1.429 (3)	C9—H9	0.9500
O1—C2	1.456 (3)	C10—C11	1.400 (3)
O2—C1	1.415 (3)	C10—C13	1.468 (3)
O2—H2	0.8400	C11—C12	1.394 (4)
O3—C3	1.433 (3)	C11—H11	0.9500
O3—H3	0.8400	C12—H12	0.9500
O4—C4	1.421 (3)	C13—C14	1.323 (3)
O4—H4	0.8400	C13—H13	0.9500
O5—C5	1.417 (3)	C14—C15	1.485 (4)
O5—H5	0.8400	C14—H14	0.9500
O6—C7	1.387 (3)	C15—C16	1.487 (3)
O6—C6	1.411 (3)	C16—C21	1.391 (3)
O7—C15	1.241 (3)	C16—C17	1.413 (4)
C1—C2	1.511 (4)	C17—C18	1.371 (4)
C1—H1A	0.9900	C17—H17	0.9500
C1—H1B	0.9900	C18—C19	1.382 (3)
C2—C3	1.535 (4)	C18—H18	0.9500
C2—H2A	1.0000	C19—C20	1.378 (3)
C3—C4	1.511 (4)	C20—C21	1.392 (3)
C3—H3A	1.0000	C20—H20	0.9500
C4—C5	1.524 (4)	C21—H21	0.9500
C4—H4A	1.0000	O8—C22	1.429 (3)
C5—C6	1.526 (3)	O8—H8A	0.8400
C5—H5A	1.0000	C22—C23	1.523 (4)
C6—H6	1.0000	C22—H22A	0.9900
C7—C12	1.384 (4)	C22—H22B	0.9900
C7—C8	1.385 (4)	C23—H23A	0.9800
C8—C9	1.387 (4)	C23—H23B	0.9800
C8—H8	0.9500	C23—H23C	0.9800

C6—O1—C2	114.0 (2)	C8—C9—H9	119.0
C1—O2—H2	109.5	C9—C10—C11	118.2 (3)
C3—O3—H3	109.5	C9—C10—C13	118.0 (2)
C4—O4—H4	109.5	C11—C10—C13	123.8 (2)
C5—O5—H5	109.5	C12—C11—C10	120.4 (3)
C7—O6—C6	116.9 (2)	C12—C11—H11	119.8
O2—C1—C2	112.1 (2)	C10—C11—H11	119.8
O2—C1—H1A	109.2	C7—C12—C11	120.0 (3)
C2—C1—H1A	109.2	C7—C12—H12	120.0
O2—C1—H1B	109.2	C11—C12—H12	120.0
C2—C1—H1B	109.2	C14—C13—C10	129.2 (2)
H1A—C1—H1B	107.9	C14—C13—H13	115.4
O1—C2—C1	106.8 (2)	C10—C13—H13	115.4
O1—C2—C3	109.3 (2)	C13—C14—C15	118.5 (2)
C1—C2—C3	113.5 (3)	C13—C14—H14	120.8
O1—C2—H2A	109.0	C15—C14—H14	120.8
C1—C2—H2A	109.0	O7—C15—C14	120.6 (2)
C3—C2—H2A	109.0	O7—C15—C16	119.2 (3)
O3—C3—C4	111.4 (2)	C14—C15—C16	120.2 (2)
O3—C3—C2	108.7 (2)	C21—C16—C17	118.6 (2)
C4—C3—C2	109.8 (2)	C21—C16—C15	123.4 (2)
O3—C3—H3A	109.0	C17—C16—C15	118.0 (2)
C4—C3—H3A	109.0	C18—C17—C16	120.6 (3)
C2—C3—H3A	109.0	C18—C17—H17	119.7
O4—C4—C3	107.7 (2)	C16—C17—H17	119.7
O4—C4—C5	110.8 (2)	C17—C18—C19	119.5 (3)
C3—C4—C5	109.9 (2)	C17—C18—H18	120.2
O4—C4—H4A	109.5	C19—C18—H18	120.2
C3—C4—H4A	109.5	C20—C19—C18	121.5 (2)
C5—C4—H4A	109.5	C20—C19—Br1	119.5 (2)
O5—C5—C4	113.6 (2)	C18—C19—Br1	119.0 (2)
O5—C5—C6	112.8 (2)	C19—C20—C21	119.1 (2)
C4—C5—C6	106.9 (2)	C19—C20—H20	120.4
O5—C5—H5A	107.8	C21—C20—H20	120.4
C4—C5—H5A	107.8	C16—C21—C20	120.6 (2)
C6—C5—H5A	107.8	C16—C21—H21	119.7
O6—C6—O1	106.3 (2)	C20—C21—H21	119.7
O6—C6—C5	108.9 (2)	C22—O8—H8A	109.5
O1—C6—C5	109.8 (2)	O8—C22—C23	111.9 (2)
O6—C6—H6	110.6	O8—C22—H22A	109.2
O1—C6—H6	110.6	C23—C22—H22A	109.2
C5—C6—H6	110.6	O8—C22—H22B	109.2
C12—C7—C8	120.5 (3)	C23—C22—H22B	109.2
C12—C7—O6	115.1 (2)	H22A—C22—H22B	107.9
C8—C7—O6	124.4 (3)	C22—C23—H23A	109.5
C7—C8—C9	118.9 (3)	C22—C23—H23B	109.5
C7—C8—H8	120.5	H23A—C23—H23B	109.5
C9—C8—H8	120.5	C22—C23—H23C	109.5
C10—C9—C8	122.1 (3)	H23A—C23—H23C	109.5
C10—C9—H9	119.0	H23B—C23—H23C	109.5

C6—O1—C2—C1	−179.3 (2)	C7—C8—C9—C10	−0.4 (5)
C6—O1—C2—C3	57.5 (3)	C8—C9—C10—C11	−0.7 (5)
O2—C1—C2—O1	−59.0 (3)	C8—C9—C10—C13	177.9 (3)
O2—C1—C2—C3	61.6 (3)	C9—C10—C11—C12	1.3 (5)
O1—C2—C3—O3	−176.5 (2)	C13—C10—C11—C12	−177.2 (3)
C1—C2—C3—O3	64.4 (3)	C8—C7—C12—C11	−0.3 (4)
O1—C2—C3—C4	−54.5 (3)	O6—C7—C12—C11	−179.5 (3)
C1—C2—C3—C4	−173.6 (2)	C10—C11—C12—C7	−0.8 (5)
O3—C3—C4—O4	57.7 (3)	C9—C10—C13—C14	−174.7 (4)
C2—C3—C4—O4	−62.7 (3)	C11—C10—C13—C14	3.8 (6)
O3—C3—C4—C5	178.6 (2)	C10—C13—C14—C15	176.7 (3)
C2—C3—C4—C5	58.1 (3)	C13—C14—C15—O7	9.0 (4)
O4—C4—C5—O5	−66.2 (3)	C13—C14—C15—C16	−169.0 (3)
C3—C4—C5—O5	174.9 (2)	O7—C15—C16—C21	−172.2 (3)
O4—C4—C5—C6	58.8 (3)	C14—C15—C16—C21	5.7 (4)
C3—C4—C5—C6	−60.1 (3)	O7—C15—C16—C17	6.2 (4)
C7—O6—C6—O1	−76.7 (3)	C14—C15—C16—C17	−175.8 (3)
C7—O6—C6—C5	165.1 (2)	C21—C16—C17—C18	3.1 (4)
C2—O1—C6—O6	−179.19 (19)	C15—C16—C17—C18	−175.5 (3)
C2—O1—C6—C5	−61.5 (3)	C16—C17—C18—C19	0.0 (4)
O5—C5—C6—O6	−57.9 (3)	C17—C18—C19—C20	−2.3 (5)
C4—C5—C6—O6	176.6 (2)	C17—C18—C19—Br1	175.7 (2)
O5—C5—C6—O1	−173.9 (2)	C18—C19—C20—C21	1.5 (5)
C4—C5—C6—O1	60.6 (3)	Br1—C19—C20—C21	−176.5 (3)
C6—O6—C7—C12	−176.9 (3)	C17—C16—C21—C20	−3.9 (5)
C6—O6—C7—C8	3.9 (4)	C15—C16—C21—C20	174.6 (3)
C12—C7—C8—C9	0.9 (4)	C19—C20—C21—C16	1.6 (6)
O6—C7—C8—C9	−179.9 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O3ⁱ	0.84	1.97	2.783 (3)	164
O3—H3···O7ⁱⁱ	0.84	2.05	2.702 (3)	134
O3—H3···O4	0.84	2.38	2.786 (3)	110
O4—H4···O2ⁱⁱⁱ	0.84	1.85	2.677 (3)	166
O5—H5···O8^iv	0.84	1.91	2.678 (3)	152
O8—H8A···O1^iv	0.84	2.08	2.893 (3)	163

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

Experimental details

Crystal data
Chemical formula	C₂₁H₂₁BrO₇·C₂H₆O
M_r	511.36
Crystal system, space group	Monoclinic, P2₁
Temperature (K)	113
a, b, c (Å)	10.977 (2), 7.6518 (15), 13.259 (3)
β (°)	92.08 (3)
V (Å³)	1113.0 (4)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	1.89
Crystal size (mm)	0.20 × 0.16 × 0.12

Data collection
Diffractometer	Rigaku Saturn CCD area-detector diffractometer
Absorption correction	Multi-scan (CrystalClear; Rigaku/MSC, 2005)
T_min, T_max	0.703, 0.805
No. of measured, independent and observed [I > 2σ(I)] reflections	9199, 5171, 3636
R_int	0.039
(sin θ/λ)_max (Å⁻¹)	0.658

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.032, 0.056, 0.75
No. of reflections	5171
No. of parameters	296
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.67, −0.39
Absolute structure	Flack (1983), 2358 Friedel pairs
Absolute structure parameter	0.027 (6)

Computer programs: CrystalClear (Rigaku/MSC, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008), SHELXTL (Sheldrick, 2008.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O3ⁱ	0.84	1.97	2.783 (3)	164.3
O3—H3···O7ⁱⁱ	0.84	2.05	2.702 (3)	133.6
O3—H3···O4	0.84	2.38	2.786 (3)	110.4
O4—H4···O2ⁱⁱⁱ	0.84	1.85	2.677 (3)	166.0
O5—H5···O8^iv	0.84	1.91	2.678 (3)	151.7
O8—H8A···O1^iv	0.84	2.08	2.893 (3)	162.9

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

Acknowledgements

The authors thank Mr Zhi-Hua Mao of the Analytical & Testing Center of Sichuan University for the X-ray data collection.

References

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