4-Formyl­phenyl 2,3,4,6-tetra-O-acetyl-β-d-galactopyran­oside

Hussen, R.S.D.; Heidelberg, T.; Rodzi, N.Z.M.; Ng, S.W.; Tiekink, E.R.T.

doi:10.1107/S1600536811008257

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 67| Part 4| April 2011| Page o826

doi:10.1107/S1600536811008257

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4-Formylphenyl 2,3,4,6-tetra-O-acetyl-β-D-galactopyranoside

Rusnah Syahila Duali Hussen,^a Thorsten Heidelberg,^a ‡ Nasrul Zamani Mohd Rodzi,^a Seik Weng Ng ^a and Edward R. T. Tiekink ^a ^*

^aDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
^*Correspondence e-mail: edward.tiekink@gmail.com

(Received 16 February 2011; accepted 3 March 2011; online 9 March 2011)

The galactose ring in the title compound, C₂₁H₂₄O₁₁, has a chair conformation with the substituted benzene ring occupying an equatorial position. The crystal packing features C—H⋯O interactions that lead to the formation of supramolecular layers in the ab plane.

Related literature

For the synthesis, see: Benassi et al. (2007 ); Patil et al. (2008 ). For the biological activity of related structures, see: Zheng et al. (2010 ). For the structure of the isomeric allopyranoside and glucopyranoside derivatives, see: Ye et al. (2009 ); Heidelberg et al. (2011 ). For conformational analysis, see: Cremer & Pople (1975 ).

Experimental

Crystal data

C₂₁H₂₄O₁₁
M_r = 452.40
Monoclinic, P 2₁
a = 11.8358 (4) Å
b = 5.6664 (2) Å
c = 17.5079 (6) Å
β = 109.616 (4)°
V = 1106.05 (7) Å³
Z = 2
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 100 K
0.25 × 0.20 × 0.05 mm

Data collection

Agilent Supernova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010 ) T_min = 0.596, T_max = 1.000
10396 measured reflections
2768 independent reflections
2535 reflections with I > 2σ(I)
R_int = 0.051

Refinement

R[F² > 2σ(F²)] = 0.035
wR(F²) = 0.086
S = 1.05
2768 reflections
293 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3⋯O9ⁱ	1.00	2.39	3.199 (3)	137
C5—H5⋯O9ⁱ	1.00	2.45	3.268 (3)	139
C10—H10b⋯O3ⁱⁱ	0.98	2.46	3.307 (3)	145
C12—H12b⋯O5ⁱⁱⁱ	0.98	2.57	3.548 (3)	172
C14—H14c⋯O11^iv	0.98	2.50	3.415 (4)	155
Symmetry codes: (i) x, y-1, z; (ii) x, y+1, z; (iii) $[-x+2, y+{\script{1\over 2}}, -z+1]$ ; (iv) x+1, y, z.

Data collection: CrysAlis PRO (Agilent, 2010); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997 ) and DIAMOND (Brandenburg, 2006 ); software used to prepare material for publication: publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811008257/ez2236sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811008257/ez2236Isup2.hkl

checkCIF report

Comment top

The title compound, 4-formyl-phenyl 2,3,4,6-tetra-O-acetyl-β-D-galactopyranoside, a known species (Benassi et al., 2007; Patil et al., 2008), was prepared as a precursor for the synthesis of galactosylated resveratrol, an anti-oxidizing agent with possible pharmaceutical potential (Zheng et al., 2010).

The structure determination, Fig. 1, confirms the relative stereochemistry. The absolute structure, while not determined experimentally, is based on that of the acetobromogalactose reagent, i.e. R, S, S, R and S for C1–C5, respectively. The galactose ring has a chair conformation as seen in the puckering parameters (Cremer & Pople, 1975): puckering amplitude (Q) = 0.579 (2) Å, θ = 166.9 (2) °, and ϕ = 187.6 (10) °. Around the ring, the substituents at the C1, C4 and C5 atoms are equatorial, while at C2 the substituent is axial and that at the C3 atom is biaxial.

The crystal packing is dominated by C–H···O interactions, Table 1, involving all carbonyl atoms, except the O7 atom, as acceptors and either methine- or methyl-H as the donors. These lead to the formation of supramolecular layers that stack along the c axis, Fig. 2.

The present report complements the structures reported recently for the isomeric allopyranoside (Ye et al., 2009) and glucopyranoside (Heidelberg et al., 2011) derivatives.

Related literature top

For the synthesis, see: Benassi et al. (2007); Patil et al. (2008). For the biological activity of related structures, see: Zheng et al. (2010). For the structure of the isomeric allopyranoside and glucopyranoside derivatives, see: Ye et al. (2009); Heidelberg et al. (2011). For conformational analysis, see: Cremer & Pople (1975).

Experimental top

2,3,4,6-Tetra-O-acetyl-α-D-galactopyranosyl bromide (2.0 g) and 4-hydroxybenzaldehyde (1.0 g) were dissolved in chloroform (10 ml) and the mixture was treated with an aqueous solution (5 ml) of sodium carbonate (0.9 g) and tetrabutylammonium bromide (0.3 g). The mixture was heated to reflux under vigorous stirring overnight, after which ethyl acetate was added and the organic layer was washed three times with sodium hydroxide solution (1 N) to remove remaining phenols. After drying the solution over magnesium sulfate and evaporation of the solvent, the target product (1.4 g, 60%) was obtained by crystallization from 2-propanol/hexane (2:1).

¹H-NMR (400 MHz, CDCl₃): δ 9.93 (s; CHO), 7.85 & 7.11 (AB syst; aromatic 4 H), 5.52 (dd; H2), 5.48 (bd; H4), 5.17 (d; H1), 5.12 (dd; H3), 4.23 (dd; H6a), 4.19–4.10 (m, 2 H; H5, H6b), 2.19–2.02 (3 s, 12 H; Ac); ³J_4,5 = 10.0 Hz, ³J_5,6a = 5.0 Hz, ³J_{5,6 b} = 2.5 Hz, ²J₆ = 12.0 Hz.

Computing details top

Data collection: CrysAlis PRO (Agilent, 2010); cell refinement: CrysAlis PRO (Agilent, 2010); data reduction: CrysAlis PRO (Agilent, 2010); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top

	Fig. 1. Molecular structure, showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level.
	Fig. 2. A view in projection down the b axis of the unit-cell contents highlighting the stacking of layers. The C—H···O interactions are shown as orange dashed lines.

4-Formylphenyl 2,3,4,6-tetra-O-acetyl-β-D-galactopyranoside top

Crystal data top

C₂₁H₂₄O₁₁	F(000) = 476
M_r = 452.40	D_x = 1.358 Mg m⁻³
Monoclinic, P2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 5487 reflections
a = 11.8358 (4) Å	θ = 2.5–29.3°
b = 5.6664 (2) Å	µ = 0.11 mm⁻¹
c = 17.5079 (6) Å	T = 100 K
β = 109.616 (4)°	Prism, colourless
V = 1106.05 (7) Å³	0.25 × 0.20 × 0.05 mm
Z = 2

Data collection top

Agilent Supernova Dual diffractometer with an Atlas detector	2768 independent reflections
Radiation source: SuperNova (Mo) X-ray Source	2535 reflections with I > 2σ(I)
Mirror monochromator	R_int = 0.051
Detector resolution: 10.4041 pixels mm^-1	θ_max = 27.5°, θ_min = 2.5°
ω scans	h = −15→15
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010)	k = −7→6
T_min = 0.596, T_max = 1.000	l = −22→16
10396 measured 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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.086	H-atom parameters constrained
S = 1.05	w = 1/[σ²(F_o²) + (0.0424P)² + 0.1621P] where P = (F_o² + 2F_c²)/3
2768 reflections	(Δ/σ)_max < 0.001
293 parameters	Δρ_max = 0.21 e Å⁻³
1 restraint	Δρ_min = −0.21 e Å⁻³

Crystal data top

C₂₁H₂₄O₁₁	V = 1106.05 (7) Å³
M_r = 452.40	Z = 2
Monoclinic, P2₁	Mo Kα radiation
a = 11.8358 (4) Å	µ = 0.11 mm⁻¹
b = 5.6664 (2) Å	T = 100 K
c = 17.5079 (6) Å	0.25 × 0.20 × 0.05 mm
β = 109.616 (4)°

Data collection top

Agilent Supernova Dual diffractometer with an Atlas detector	2768 independent reflections
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010)	2535 reflections with I > 2σ(I)
T_min = 0.596, T_max = 1.000	R_int = 0.051
10396 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.035	1 restraint
wR(F²) = 0.086	H-atom parameters constrained
S = 1.05	Δρ_max = 0.21 e Å⁻³
2768 reflections	Δρ_min = −0.21 e Å⁻³
293 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
O1	0.52081 (12)	0.4982 (3)	0.29215 (8)	0.0188 (3)
O2	0.48738 (13)	0.0896 (3)	0.37091 (9)	0.0240 (4)
O3	0.55891 (13)	−0.1643 (3)	0.47497 (9)	0.0243 (4)
O4	0.75837 (12)	0.6298 (3)	0.39447 (8)	0.0184 (3)
O5	0.86847 (14)	0.3841 (3)	0.49186 (9)	0.0283 (4)
O6	0.83224 (12)	0.7065 (3)	0.26663 (8)	0.0202 (3)
O7	0.95682 (14)	0.3988 (3)	0.27801 (9)	0.0271 (4)
O8	0.61785 (14)	0.7131 (3)	0.12877 (9)	0.0202 (3)
O9	0.61716 (16)	1.1080 (3)	0.13951 (10)	0.0304 (4)
O10	0.41232 (13)	0.7100 (3)	0.18039 (8)	0.0213 (3)
O11	−0.15194 (15)	0.5245 (5)	0.06218 (12)	0.0490 (6)
C1	0.61385 (17)	0.3269 (4)	0.32349 (12)	0.0180 (4)
H1	0.6016	0.1990	0.2821	0.022*
C2	0.73547 (18)	0.4392 (4)	0.33610 (12)	0.0178 (4)
H2	0.8001	0.3174	0.3549	0.021*
C3	0.73421 (17)	0.5437 (4)	0.25518 (12)	0.0177 (4)
H3	0.7421	0.4124	0.2191	0.021*
C4	0.62145 (17)	0.6840 (4)	0.21135 (11)	0.0177 (4)
H4	0.6253	0.8420	0.2376	0.021*
C5	0.50894 (18)	0.5541 (4)	0.21107 (12)	0.0182 (4)
H5	0.4966	0.4081	0.1772	0.022*
C6	0.59907 (18)	0.2203 (4)	0.39814 (12)	0.0216 (5)
H6A	0.6670	0.1138	0.4253	0.026*
H6B	0.5958	0.3454	0.4368	0.026*
C7	0.47923 (18)	−0.0968 (4)	0.41586 (12)	0.0205 (4)
C8	0.35738 (19)	−0.2058 (5)	0.38251 (13)	0.0272 (5)
H8A	0.3622	−0.3731	0.3974	0.041*
H8B	0.3277	−0.1909	0.3233	0.041*
H8C	0.3024	−0.1247	0.4049	0.041*
C9	0.83088 (18)	0.5785 (4)	0.47134 (12)	0.0195 (4)
C10	0.8534 (2)	0.7915 (4)	0.52407 (13)	0.0246 (5)
H10A	0.9152	0.7559	0.5762	0.037*
H10B	0.7791	0.8375	0.5332	0.037*
H10C	0.8807	0.9212	0.4976	0.037*
C11	0.94103 (19)	0.6087 (5)	0.27887 (12)	0.0221 (5)
C12	1.0356 (2)	0.7935 (5)	0.29539 (14)	0.0301 (6)
H12A	1.0988	0.7413	0.2746	0.045*
H12B	1.0701	0.8202	0.3540	0.045*
H12C	1.0003	0.9407	0.2684	0.045*
C13	0.61949 (19)	0.9346 (4)	0.10083 (13)	0.0208 (5)
C14	0.6223 (2)	0.9316 (5)	0.01601 (13)	0.0284 (5)
H14A	0.6497	1.0852	0.0034	0.043*
H14B	0.5416	0.8993	−0.0219	0.043*
H14C	0.6774	0.8081	0.0111	0.043*
C15	0.29775 (18)	0.6182 (5)	0.16131 (12)	0.0214 (5)
C16	0.2083 (2)	0.7649 (5)	0.11247 (13)	0.0269 (5)
H16	0.2281	0.9110	0.0935	0.032*
C17	0.0891 (2)	0.6936 (5)	0.09193 (14)	0.0310 (6)
H17	0.0271	0.7924	0.0588	0.037*
C18	0.0601 (2)	0.4804 (5)	0.11914 (13)	0.0282 (5)
C19	0.1514 (2)	0.3361 (5)	0.16730 (13)	0.0275 (5)
H19	0.1317	0.1889	0.1856	0.033*
C20	0.27087 (19)	0.4037 (4)	0.18905 (13)	0.0246 (5)
H20	0.3328	0.3050	0.2222	0.030*
C21	−0.0667 (2)	0.4052 (6)	0.09904 (14)	0.0369 (6)
H21	−0.0816	0.2530	0.1163	0.044*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0204 (7)	0.0207 (8)	0.0147 (7)	0.0044 (6)	0.0053 (6)	0.0017 (6)
O2	0.0208 (7)	0.0267 (9)	0.0219 (7)	−0.0005 (7)	0.0037 (6)	0.0064 (7)
O3	0.0241 (7)	0.0252 (9)	0.0233 (7)	−0.0009 (7)	0.0075 (6)	0.0057 (7)
O4	0.0216 (7)	0.0151 (7)	0.0159 (6)	0.0016 (6)	0.0025 (6)	−0.0009 (6)
O5	0.0353 (9)	0.0198 (9)	0.0226 (7)	0.0033 (7)	0.0000 (7)	0.0025 (7)
O6	0.0205 (7)	0.0175 (8)	0.0231 (7)	−0.0019 (6)	0.0081 (6)	−0.0008 (6)
O7	0.0248 (8)	0.0258 (10)	0.0309 (8)	0.0023 (7)	0.0095 (7)	0.0016 (8)
O8	0.0305 (8)	0.0153 (8)	0.0149 (7)	0.0001 (7)	0.0078 (6)	−0.0004 (6)
O9	0.0498 (10)	0.0161 (8)	0.0268 (8)	−0.0001 (8)	0.0148 (8)	0.0009 (8)
O10	0.0211 (7)	0.0181 (8)	0.0220 (7)	0.0049 (6)	0.0035 (6)	0.0020 (7)
O11	0.0240 (9)	0.0789 (17)	0.0400 (11)	0.0101 (10)	0.0052 (8)	−0.0055 (11)
C1	0.0201 (9)	0.0133 (10)	0.0193 (9)	0.0013 (9)	0.0048 (8)	0.0014 (8)
C2	0.0214 (10)	0.0131 (11)	0.0181 (9)	0.0008 (8)	0.0054 (8)	−0.0015 (8)
C3	0.0189 (10)	0.0142 (11)	0.0200 (10)	−0.0020 (8)	0.0064 (8)	−0.0014 (8)
C4	0.0238 (10)	0.0151 (11)	0.0144 (9)	0.0020 (9)	0.0065 (8)	0.0005 (8)
C5	0.0218 (10)	0.0146 (11)	0.0168 (9)	0.0034 (8)	0.0048 (8)	0.0008 (8)
C6	0.0197 (10)	0.0224 (12)	0.0204 (10)	−0.0029 (9)	0.0039 (8)	0.0039 (9)
C7	0.0219 (10)	0.0206 (11)	0.0217 (10)	−0.0018 (9)	0.0107 (9)	−0.0013 (9)
C8	0.0241 (11)	0.0309 (14)	0.0266 (11)	−0.0053 (10)	0.0087 (9)	0.0010 (11)
C9	0.0172 (9)	0.0210 (12)	0.0180 (9)	−0.0019 (9)	0.0027 (8)	0.0022 (9)
C10	0.0272 (11)	0.0224 (12)	0.0200 (10)	0.0011 (10)	0.0024 (9)	−0.0004 (10)
C11	0.0230 (10)	0.0270 (13)	0.0167 (9)	−0.0005 (10)	0.0072 (8)	−0.0005 (10)
C12	0.0255 (11)	0.0358 (15)	0.0290 (11)	−0.0071 (11)	0.0092 (10)	−0.0055 (11)
C13	0.0214 (10)	0.0174 (12)	0.0222 (10)	0.0005 (9)	0.0056 (9)	0.0034 (9)
C14	0.0380 (12)	0.0267 (14)	0.0215 (10)	0.0039 (11)	0.0113 (10)	0.0041 (10)
C15	0.0213 (10)	0.0248 (12)	0.0170 (9)	0.0027 (9)	0.0050 (8)	−0.0051 (9)
C16	0.0297 (12)	0.0280 (13)	0.0216 (10)	0.0069 (10)	0.0067 (10)	0.0003 (10)
C17	0.0243 (11)	0.0433 (16)	0.0222 (10)	0.0113 (11)	0.0036 (9)	−0.0008 (11)
C18	0.0252 (11)	0.0389 (15)	0.0201 (10)	0.0029 (11)	0.0070 (9)	−0.0085 (11)
C19	0.0269 (11)	0.0276 (13)	0.0279 (11)	−0.0027 (10)	0.0091 (10)	−0.0070 (10)
C20	0.0227 (10)	0.0235 (12)	0.0250 (10)	0.0036 (10)	0.0046 (9)	−0.0003 (10)
C21	0.0257 (12)	0.0567 (19)	0.0284 (12)	0.0004 (13)	0.0092 (10)	−0.0121 (13)

Geometric parameters (Å, º) top

O1—C5	1.415 (2)	C7—C8	1.496 (3)
O1—C1	1.432 (2)	C8—H8A	0.9800
O2—C7	1.340 (3)	C8—H8B	0.9800
O2—C6	1.449 (3)	C8—H8C	0.9800
O3—C7	1.205 (3)	C9—C10	1.488 (3)
O4—C9	1.362 (2)	C10—H10A	0.9800
O4—C2	1.448 (2)	C10—H10B	0.9800
O5—C9	1.197 (3)	C10—H10C	0.9800
O6—C11	1.351 (3)	C11—C12	1.489 (3)
O6—C3	1.443 (2)	C12—H12A	0.9800
O7—C11	1.205 (3)	C12—H12B	0.9800
O8—C13	1.350 (3)	C12—H12C	0.9800
O8—C4	1.441 (2)	C13—C14	1.497 (3)
O9—C13	1.199 (3)	C14—H14A	0.9800
O10—C15	1.384 (3)	C14—H14B	0.9800
O10—C5	1.401 (2)	C14—H14C	0.9800
O11—C21	1.206 (3)	C15—C20	1.385 (3)
C1—C6	1.502 (3)	C15—C16	1.391 (3)
C1—C2	1.521 (3)	C16—C17	1.393 (3)
C1—H1	1.0000	C16—H16	0.9500
C2—C3	1.531 (3)	C17—C18	1.384 (4)
C2—H2	1.0000	C17—H17	0.9500
C3—C4	1.521 (3)	C18—C19	1.391 (3)
C3—H3	1.0000	C18—C21	1.484 (3)
C4—C5	1.520 (3)	C19—C20	1.389 (3)
C4—H4	1.0000	C19—H19	0.9500
C5—H5	1.0000	C20—H20	0.9500
C6—H6A	0.9900	C21—H21	0.9500
C6—H6B	0.9900

C5—O1—C1	109.93 (14)	H8B—C8—H8C	109.5
C7—O2—C6	116.57 (16)	O5—C9—O4	122.7 (2)
C9—O4—C2	116.39 (17)	O5—C9—C10	126.07 (19)
C11—O6—C3	116.03 (17)	O4—C9—C10	111.22 (19)
C13—O8—C4	118.07 (17)	C9—C10—H10A	109.5
C15—O10—C5	117.57 (17)	C9—C10—H10B	109.5
O1—C1—C6	107.86 (16)	H10A—C10—H10B	109.5
O1—C1—C2	109.91 (17)	C9—C10—H10C	109.5
C6—C1—C2	115.02 (17)	H10A—C10—H10C	109.5
O1—C1—H1	107.9	H10B—C10—H10C	109.5
C6—C1—H1	107.9	O7—C11—O6	123.1 (2)
C2—C1—H1	107.9	O7—C11—C12	125.9 (2)
O4—C2—C1	111.00 (16)	O6—C11—C12	110.9 (2)
O4—C2—C3	107.82 (17)	C11—C12—H12A	109.5
C1—C2—C3	108.23 (16)	C11—C12—H12B	109.5
O4—C2—H2	109.9	H12A—C12—H12B	109.5
C1—C2—H2	109.9	C11—C12—H12C	109.5
C3—C2—H2	109.9	H12A—C12—H12C	109.5
O6—C3—C4	105.32 (16)	H12B—C12—H12C	109.5
O6—C3—C2	111.18 (16)	O9—C13—O8	123.49 (19)
C4—C3—C2	113.79 (16)	O9—C13—C14	125.6 (2)
O6—C3—H3	108.8	O8—C13—C14	110.91 (19)
C4—C3—H3	108.8	C13—C14—H14A	109.5
C2—C3—H3	108.8	C13—C14—H14B	109.5
O8—C4—C5	108.73 (16)	H14A—C14—H14B	109.5
O8—C4—C3	106.93 (15)	C13—C14—H14C	109.5
C5—C4—C3	111.57 (17)	H14A—C14—H14C	109.5
O8—C4—H4	109.9	H14B—C14—H14C	109.5
C5—C4—H4	109.9	O10—C15—C20	124.53 (19)
C3—C4—H4	109.9	O10—C15—C16	113.9 (2)
O10—C5—O1	108.61 (15)	C20—C15—C16	121.5 (2)
O10—C5—C4	107.29 (17)	C15—C16—C17	118.7 (2)
O1—C5—C4	108.26 (16)	C15—C16—H16	120.6
O10—C5—H5	110.9	C17—C16—H16	120.6
O1—C5—H5	110.9	C18—C17—C16	120.8 (2)
C4—C5—H5	110.9	C18—C17—H17	119.6
O2—C6—C1	106.20 (16)	C16—C17—H17	119.6
O2—C6—H6A	110.5	C17—C18—C19	119.3 (2)
C1—C6—H6A	110.5	C17—C18—C21	121.1 (2)
O2—C6—H6B	110.5	C19—C18—C21	119.5 (3)
C1—C6—H6B	110.5	C20—C19—C18	121.1 (2)
H6A—C6—H6B	108.7	C20—C19—H19	119.5
O3—C7—O2	124.39 (19)	C18—C19—H19	119.5
O3—C7—C8	125.4 (2)	C15—C20—C19	118.6 (2)
O2—C7—C8	110.25 (18)	C15—C20—H20	120.7
C7—C8—H8A	109.5	C19—C20—H20	120.7
C7—C8—H8B	109.5	O11—C21—C18	124.3 (3)
H8A—C8—H8B	109.5	O11—C21—H21	117.8
C7—C8—H8C	109.5	C18—C21—H21	117.8
H8A—C8—H8C	109.5

C5—O1—C1—C6	−163.31 (17)	C3—C4—C5—O1	54.5 (2)
C5—O1—C1—C2	70.6 (2)	C7—O2—C6—C1	151.59 (18)
C9—O4—C2—C1	100.1 (2)	O1—C1—C6—O2	66.5 (2)
C9—O4—C2—C3	−141.53 (17)	C2—C1—C6—O2	−170.44 (17)
O1—C1—C2—O4	61.5 (2)	C6—O2—C7—O3	−2.2 (3)
C6—C1—C2—O4	−60.5 (2)	C6—O2—C7—C8	177.27 (18)
O1—C1—C2—C3	−56.7 (2)	C2—O4—C9—O5	−4.5 (3)
C6—C1—C2—C3	−178.60 (18)	C2—O4—C9—C10	176.56 (17)
C11—O6—C3—C4	−158.49 (16)	C3—O6—C11—O7	2.3 (3)
C11—O6—C3—C2	77.8 (2)	C3—O6—C11—C12	−176.14 (16)
O4—C2—C3—O6	44.2 (2)	C4—O8—C13—O9	−4.2 (3)
C1—C2—C3—O6	164.33 (16)	C4—O8—C13—C14	176.78 (17)
O4—C2—C3—C4	−74.5 (2)	C5—O10—C15—C20	17.7 (3)
C1—C2—C3—C4	45.6 (2)	C5—O10—C15—C16	−164.09 (18)
C13—O8—C4—C5	120.0 (2)	O10—C15—C16—C17	−177.76 (19)
C13—O8—C4—C3	−119.44 (19)	C20—C15—C16—C17	0.5 (3)
O6—C3—C4—O8	73.70 (19)	C15—C16—C17—C18	−0.3 (3)
C2—C3—C4—O8	−164.29 (17)	C16—C17—C18—C19	−0.2 (3)
O6—C3—C4—C5	−167.54 (16)	C16—C17—C18—C21	178.7 (2)
C2—C3—C4—C5	−45.5 (2)	C17—C18—C19—C20	0.6 (3)
C15—O10—C5—O1	−74.1 (2)	C21—C18—C19—C20	−178.3 (2)
C15—O10—C5—C4	169.11 (16)	O10—C15—C20—C19	177.9 (2)
C1—O1—C5—O10	176.18 (16)	C16—C15—C20—C19	−0.2 (3)
C1—O1—C5—C4	−67.6 (2)	C18—C19—C20—C15	−0.4 (3)
O8—C4—C5—O10	−70.80 (19)	C17—C18—C21—O11	−3.8 (4)
C3—C4—C5—O10	171.51 (15)	C19—C18—C21—O11	175.1 (2)
O8—C4—C5—O1	172.16 (16)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O9ⁱ	1.00	2.39	3.199 (3)	137
C5—H5···O9ⁱ	1.00	2.45	3.268 (3)	139
C10—H10b···O3ⁱⁱ	0.98	2.46	3.307 (3)	145
C12—H12b···O5ⁱⁱⁱ	0.98	2.57	3.548 (3)	172
C14—H14c···O11^iv	0.98	2.50	3.415 (4)	155

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

Experimental details

Crystal data
Chemical formula	C₂₁H₂₄O₁₁
M_r	452.40
Crystal system, space group	Monoclinic, P2₁
Temperature (K)	100
a, b, c (Å)	11.8358 (4), 5.6664 (2), 17.5079 (6)
β (°)	109.616 (4)
V (Å³)	1106.05 (7)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.11
Crystal size (mm)	0.25 × 0.20 × 0.05

Data collection
Diffractometer	Agilent Supernova Dual diffractometer with an Atlas detector
Absorption correction	Multi-scan (CrysAlis PRO; Agilent, 2010)
T_min, T_max	0.596, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	10396, 2768, 2535
R_int	0.051
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.035, 0.086, 1.05
No. of reflections	2768
No. of parameters	293
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.21, −0.21

Computer programs: CrysAlis PRO (Agilent, 2010), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 2006), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O9ⁱ	1.00	2.39	3.199 (3)	137
C5—H5···O9ⁱ	1.00	2.45	3.268 (3)	139
C10—H10b···O3ⁱⁱ	0.98	2.46	3.307 (3)	145
C12—H12b···O5ⁱⁱⁱ	0.98	2.57	3.548 (3)	172
C14—H14c···O11^iv	0.98	2.50	3.415 (4)	155

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

Footnotes

‡Additional correspondence author, e-mail: heidelberg@um.edu.my.

Acknowledgements

This study was supported by the University of Malaya under research grant FS306/2007 C. The authors are also grateful to the University of Malaya for support of the crystallographic facility.

References

Agilent (2010). CrysAlis PRO. Agilent Technologies, Yarnton, England. Google Scholar
Benassi, R., Ferraria, E., Grandia, R., Lazzaria, S. & Saladini, M. (2007). J. Inorg. Biochem. 101, 203–213. Web of Science CrossRef PubMed CAS Google Scholar
Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358. CrossRef CAS Web of Science Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Heidelberg, T., Hussen, R. S. D., Rodzi, N. Z. M., Ng, S. W. & Tiekink, E. R. T. (2011). Acta Cryst. E67, o825. Web of Science CSD CrossRef IUCr Journals Google Scholar
Patil, P. R. & Ravindranathan Kartha, K. P. (2008). J. Carbohydr. Chem. 27, 411–419. CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
Ye, D., Zhang, K., Chen, H., Yin, S. & Li, Y. (2009). Acta Cryst. E65, o1338. Web of Science CSD CrossRef IUCr Journals Google Scholar
Zheng, Y., Meng, X.-B., Li, S.-C., Huang, H.-Q., Li, Z.-J. & Li, Q. (2010). J. Chin. Pharm. Sci. 19, 327–340. CAS Google Scholar