3,5,7-Trimeth­oxy-2-(4-methoxy­phen­yl)-4H-1-benzopyran-4-one

Aree, T.; Sawasdee, P.

doi:10.1107/S1600536809040938

organic compounds

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ISSN: 2056-9890

Volume 65| Part 11| November 2009| Page o2706

https://doi.org/10.1107/S1600536809040938

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3,5,7-Trimethoxy-2-(4-methoxyphenyl)-4H-1-benzopyran-4-one

Thammarat Aree ^a ^* and Pattara Sawasdee ^a

^aDepartment of Chemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Pathumwan, Bangkok 10330, Thailand, and The Center for Petroleum Petrochemicals and Advanced Materials, Chulalongkorn University, Bangkok 10330, Thailand
^*Correspondence e-mail: thammarat.aree@gmail.com

(Received 4 October 2009; accepted 7 October 2009; online 10 October 2009)

In the title compound, C₁₉H₁₈O₆, also known as 3,4′,5,7-tetramethoxyflavone, the dihedral angle between the benzopyran-4-one group and the attached benzene ring is 11.23 (8)°. An intramolecular C—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, molecules are linked into a two-dimensional network parallel to (0 $[\overline{1}]$ 1) by intermolecular C—H⋯O hydrogen bonds, which generate R₄⁴(20), R₄⁴(12) and R₂²(14) ring motifs. Adjacent networks interact by π–π interactions between the pyran ring and its methoxyphenyl substituent [centroid–centroid distance = 3.5267 (8) Å].

Related literature

For related structures, see: Aree et al. (2009 ) and the Cambridge Structural Database [Allen (2002 ); Bruno et al. (2002 )]. For the graph-set description of hydrogen-bond patterns, see: Bernstein et al. (1995 ).

Experimental

Crystal data

C₁₉H₁₈O₆
M_r = 342.33
Triclinic, $[P \overline 1]$
a = 8.7854 (3) Å
b = 9.2743 (4) Å
c = 10.6950 (4) Å
α = 70.749 (1)°
β = 81.448 (1)°
γ = 83.078 (1)°
V = 811.15 (5) Å³
Z = 2
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 298 K
0.40 × 0.22 × 0.18 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ) T_min = 0.839, T_max = 0.946
5901 measured reflections
3930 independent reflections
2827 reflections with I > 2σ(I)
R_int = 0.023

Refinement

R[F² > 2σ(F²)] = 0.044
wR(F²) = 0.131
S = 1.06
3930 reflections
230 parameters
H-atom parameters constrained
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15⋯O5	0.93	2.23	2.8690 (18)	126
C17—H17B⋯O2ⁱ	0.96	2.48	3.2674 (19)	139
C17—H17B⋯O3ⁱ	0.96	2.61	3.458 (2)	148
C18—H18B⋯O6ⁱⁱ	0.96	2.57	3.530 (2)	173
C19—H19C⋯O5ⁱⁱⁱ	0.96	2.51	3.457 (2)	170
Symmetry codes: (i) -x-1, -y, -z+1; (ii) -x, -y+1, -z+2; (iii) x+1, y, z.

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: ORTEP-3 (Farrugia, 1997 ) and Mercury (Macrae et al. 2006 ).; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536809040938/ci2932sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536809040938/ci2932Isup2.hkl

checkCIF report

Comment top

The title compound, (I), (3,5,7-trimethoxy-2-(4-methoxyphenyl)-4H- 1-benzopyran-4-one or 3,4',5,7-tetramethoxyflavone), (Fig.1), is a secondary metabolite that was isolated from a Thai medicinal plant, Kaempferia parviflora. Several flavones have also been isolated from this plant and their crystal structures have been reported, for example see Aree et al. (2009) and references cited therein. Here, we report the crystal structure of another flavone in an anhydrous form having no strong hydrogen bond donor. Weak C—H···O hydrogen bonds play a key role in stabilizing the crystal lattice.

The molecular structure of (I) deviates from a planar geometry; the interplanar angle between the benzopyran-4-one group and the attached phenyl group is 11.23 (8)° (Fig. 1). A search in the Cambridge Structural Database [Version 1.11 (Allen, 2002); CONQUEST (Bruno et al., 2002)] indicate that this feature is frequently observed . The three methoxy C16, C17 and C19 atoms slightly deviate from the mean planes of the attached benzopyran or phenyl rings by 0.288 (3), -0.119 (3) and 0.355 (3) Å whereas atom C18 deviates from the benzopyran plane by -0.933 (3) Å. The corresponding values of torsion angles are C16—O4—C3—C2 = 3.0 (2)°, C17—O3—C5—C4 = 0.4 (2)°, C19—O6—C13—C12 = -15.9 (2)° and C18—O5—C8—C9 = 111.09 (17)°. The flavone molecule is stabilized by an intramolecular C15—H···O5 hydrogen bond that generates an S(6) ring motif (Bernstein et al., 1995).

In the crystal, molecules are linked to form a ribbon-like structure by intermolecular C18—H18B···O6ⁱⁱ and C19—H19C···.O5ⁱⁱⁱ hydrogen bonds, generating R₂²(20) and R₄⁴(12) ring motifs (Bernstein et al., 1995) (Fig. 2). The adjacent inversion-related ribbons are cross-linked into a two-dimensional network parallel to the (011) by intermolecular C17—H17B···O2ⁱ and C17—H17B···O3ⁱ hydrogen bonds, generating R₂²(14) ring motifs (Bernstein et al., 1995) (Fig. 3). The crystal structure is further stabilized by π–π interactions (Fig. 4) between O1/C1/C6-C9 and C10-C15 rings of the molecules in adjacent networks, with a centroid-to-centroid distance of 3.5267 (8) Å.

Related literature top

For related structures, see: Aree et al. (2009) and the Cambridge Structural Database [Allen (2002); Bruno et al. (2002)]. For the graph-set description of hydrogen-bond patterns, see: Bernstein et al. (1995).

Experimental top

The title compound, (I), was extracted from Kaempferia parviflora, a medicinal plant from the north-east of Thailand. Single crystals of (I) were obtained by slow evaporation of a methanol–water (1:1, v/v) solution at room temperature.

Structure description top

For related structures, see: Aree et al. (2009) and the Cambridge Structural Database [Allen (2002); Bruno et al. (2002)]. For the graph-set description of hydrogen-bond patterns, see: Bernstein et al. (1995).

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al. 2006).; software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of (I), with atom numbering and 50% probability displacement ellipsoids. An intramolecular C—H···O hydrogen bond forming an S(6) motif is shown as a dashed line.
	Fig. 2. Part of a ribbon formed by intermolecular C—H···O hydrogen bonds, with R₄⁴(20) and R₄⁴(12) ring motifs. Hydrogen bonds are shown as dashed lines.
	Fig. 3. A view of R₂²(14) ring motifs which connect adjacent ribbons. Hydrogen bonds are shown as dashed lines.
	Fig. 4. Part of the crystal structure of (I), showing the stacking of pyran and 4-methoxyphenyl rings. Hydrogen bonds are shown as dashed lines.

3,5,7-Trimethoxy-2-(4-methoxyphenyl)-4H-1-benzopyran-4-one top

Crystal data top

C₁₉H₁₈O₆	Z = 2
M_r = 342.33	F(000) = 360
Triclinic, P1	D_x = 1.402 Mg m⁻³
Hall symbol: -P 1	Melting point: not measured K
a = 8.7854 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.2743 (4) Å	Cell parameters from 2649 reflections
c = 10.6950 (4) Å	θ = 2.9–29.0°
α = 70.749 (1)°	µ = 0.11 mm⁻¹
β = 81.448 (1)°	T = 298 K
γ = 83.078 (1)°	Block, colourless
V = 811.15 (5) Å³	0.40 × 0.22 × 0.18 mm

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	3930 independent reflections
Radiation source: fine-focus sealed tube	2827 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.023
φ and ω scans	θ_max = 28.3°, θ_min = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −11→11
T_min = 0.839, T_max = 0.946	k = −12→12
5901 measured reflections	l = −10→14

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.131	H-atom parameters constrained
S = 1.06	w = 1/[σ²(F_o²) + (0.0642P)² + 0.0796P] where P = (F_o² + 2F_c²)/3
3930 reflections	(Δ/σ)_max = 0.001
230 parameters	Δρ_max = 0.23 e Å⁻³
0 restraints	Δρ_min = −0.19 e Å⁻³

Crystal data top

C₁₉H₁₈O₆	γ = 83.078 (1)°
M_r = 342.33	V = 811.15 (5) Å³
Triclinic, P1	Z = 2
a = 8.7854 (3) Å	Mo Kα radiation
b = 9.2743 (4) Å	µ = 0.11 mm⁻¹
c = 10.6950 (4) Å	T = 298 K
α = 70.749 (1)°	0.40 × 0.22 × 0.18 mm
β = 81.448 (1)°

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	3930 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2005)	2827 reflections with I > 2σ(I)
T_min = 0.839, T_max = 0.946	R_int = 0.023
5901 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.044	0 restraints
wR(F²) = 0.131	H-atom parameters constrained
S = 1.06	Δρ_max = 0.23 e Å⁻³
3930 reflections	Δρ_min = −0.19 e Å⁻³
230 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	0.09284 (11)	−0.00853 (11)	0.77045 (10)	0.0384 (2)
O2	−0.35336 (13)	0.11019 (15)	0.69876 (14)	0.0627 (4)
O3	−0.31863 (12)	−0.09508 (12)	0.56603 (11)	0.0472 (3)
O4	0.14430 (12)	−0.41488 (12)	0.58844 (11)	0.0491 (3)
O5	−0.22549 (11)	0.24963 (11)	0.83872 (10)	0.0417 (3)
O6	0.37277 (13)	0.34385 (13)	1.08046 (12)	0.0554 (3)
C1	0.02711 (15)	−0.08612 (15)	0.70567 (13)	0.0334 (3)
C2	0.12382 (16)	−0.20556 (15)	0.67915 (14)	0.0370 (3)
H2	0.2237	−0.2266	0.7030	0.044*
C3	0.06590 (16)	−0.29116 (15)	0.61632 (13)	0.0363 (3)
C4	−0.08153 (16)	−0.25525 (16)	0.57554 (14)	0.0377 (3)
H4	−0.1168	−0.3118	0.5298	0.045*
C5	−0.17492 (16)	−0.13643 (16)	0.60281 (13)	0.0358 (3)
C6	−0.12267 (15)	−0.04848 (15)	0.67302 (13)	0.0337 (3)
C7	−0.21732 (16)	0.07127 (16)	0.71647 (14)	0.0381 (3)
C8	−0.13869 (16)	0.14406 (16)	0.78818 (13)	0.0343 (3)
C9	0.01016 (15)	0.10572 (15)	0.81213 (13)	0.0329 (3)
C10	0.10563 (15)	0.16951 (15)	0.88037 (13)	0.0334 (3)
C11	0.26309 (17)	0.12727 (17)	0.87961 (14)	0.0397 (3)
H11	0.3069	0.0596	0.8342	0.048*
C12	0.35723 (17)	0.18231 (17)	0.94411 (15)	0.0415 (3)
H12	0.4622	0.1522	0.9415	0.050*
C13	0.29333 (17)	0.28240 (16)	1.01227 (14)	0.0383 (3)
C14	0.13743 (18)	0.32664 (18)	1.01423 (16)	0.0464 (4)
H14	0.0944	0.3944	1.0597	0.056*
C15	0.04512 (17)	0.27193 (18)	0.94994 (16)	0.0446 (4)
H15	−0.0596	0.3034	0.9526	0.054*
C16	0.2918 (2)	−0.4624 (2)	0.6324 (2)	0.0593 (5)
H16A	0.3609	−0.3837	0.5873	0.089*
H16B	0.3308	−0.5549	0.6130	0.089*
H16C	0.2838	−0.4808	0.7268	0.089*
C17	−0.3753 (2)	−0.1803 (2)	0.49641 (19)	0.0556 (4)
H17A	−0.3085	−0.1736	0.4153	0.083*
H17B	−0.4775	−0.1393	0.4756	0.083*
H17C	−0.3781	−0.2856	0.5512	0.083*
C18	−0.2656 (3)	0.3918 (2)	0.74252 (19)	0.0718 (6)
H18A	−0.1763	0.4263	0.6807	0.108*
H18B	−0.3027	0.4663	0.7866	0.108*
H18C	−0.3449	0.3787	0.6952	0.108*
C19	0.5210 (2)	0.2757 (2)	1.11183 (18)	0.0582 (5)
H19A	0.5135	0.1701	1.1643	0.087*
H19B	0.5620	0.3284	1.1615	0.087*
H19C	0.5882	0.2825	1.0309	0.087*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0329 (5)	0.0393 (5)	0.0537 (6)	0.0034 (4)	−0.0130 (4)	−0.0279 (5)
O2	0.0377 (6)	0.0752 (8)	0.0972 (9)	0.0149 (6)	−0.0282 (6)	−0.0546 (7)
O3	0.0394 (6)	0.0499 (6)	0.0641 (7)	0.0004 (5)	−0.0220 (5)	−0.0281 (5)
O4	0.0479 (6)	0.0465 (6)	0.0663 (7)	0.0043 (5)	−0.0132 (5)	−0.0356 (5)
O5	0.0376 (5)	0.0459 (6)	0.0466 (5)	0.0098 (4)	−0.0091 (4)	−0.0241 (5)
O6	0.0479 (6)	0.0617 (7)	0.0775 (8)	0.0096 (5)	−0.0264 (6)	−0.0467 (6)
C1	0.0337 (7)	0.0329 (7)	0.0381 (6)	−0.0042 (5)	−0.0073 (5)	−0.0154 (5)
C2	0.0345 (7)	0.0358 (7)	0.0451 (7)	0.0007 (6)	−0.0100 (6)	−0.0178 (6)
C3	0.0394 (8)	0.0324 (7)	0.0391 (7)	−0.0028 (6)	−0.0032 (6)	−0.0147 (6)
C4	0.0409 (8)	0.0375 (7)	0.0406 (7)	−0.0085 (6)	−0.0080 (6)	−0.0169 (6)
C5	0.0341 (7)	0.0367 (7)	0.0384 (7)	−0.0062 (6)	−0.0086 (6)	−0.0111 (6)
C6	0.0337 (7)	0.0315 (7)	0.0378 (7)	−0.0034 (5)	−0.0075 (5)	−0.0117 (5)
C7	0.0331 (7)	0.0391 (7)	0.0454 (7)	0.0000 (6)	−0.0095 (6)	−0.0167 (6)
C8	0.0334 (7)	0.0351 (7)	0.0366 (6)	0.0014 (5)	−0.0048 (5)	−0.0155 (5)
C9	0.0329 (7)	0.0318 (7)	0.0364 (6)	0.0004 (5)	−0.0048 (5)	−0.0148 (5)
C10	0.0351 (7)	0.0327 (7)	0.0351 (6)	−0.0007 (5)	−0.0075 (5)	−0.0136 (5)
C11	0.0393 (8)	0.0406 (8)	0.0473 (7)	0.0071 (6)	−0.0112 (6)	−0.0257 (6)
C12	0.0337 (7)	0.0463 (8)	0.0521 (8)	0.0076 (6)	−0.0135 (6)	−0.0256 (7)
C13	0.0408 (8)	0.0378 (7)	0.0427 (7)	0.0007 (6)	−0.0137 (6)	−0.0188 (6)
C14	0.0447 (9)	0.0502 (9)	0.0562 (9)	0.0083 (7)	−0.0116 (7)	−0.0347 (7)
C15	0.0339 (7)	0.0543 (9)	0.0563 (9)	0.0069 (7)	−0.0111 (6)	−0.0329 (7)
C16	0.0516 (10)	0.0537 (10)	0.0871 (13)	0.0130 (8)	−0.0179 (9)	−0.0436 (9)
C17	0.0490 (10)	0.0620 (10)	0.0707 (11)	−0.0037 (8)	−0.0254 (8)	−0.0333 (9)
C18	0.1032 (16)	0.0453 (10)	0.0648 (11)	0.0232 (10)	−0.0173 (11)	−0.0217 (9)
C19	0.0463 (9)	0.0770 (12)	0.0683 (11)	0.0066 (9)	−0.0231 (8)	−0.0427 (10)

Geometric parameters (Å, º) top

O1—C9	1.3707 (15)	C10—C11	1.3912 (19)
O1—C1	1.3708 (15)	C10—C15	1.4018 (19)
O2—C7	1.2300 (17)	C11—C12	1.3871 (19)
O3—C5	1.3517 (16)	C11—H11	0.93
O3—C17	1.4212 (17)	C12—C13	1.381 (2)
O4—C3	1.3616 (16)	C12—H12	0.93
O4—C16	1.4150 (19)	C13—C14	1.381 (2)
O5—C8	1.3707 (16)	C14—C15	1.372 (2)
O5—C18	1.422 (2)	C14—H14	0.93
O6—C13	1.3657 (16)	C15—H15	0.93
O6—C19	1.4141 (19)	C16—H16A	0.96
C1—C6	1.3860 (18)	C16—H16B	0.96
C1—C2	1.3921 (18)	C16—H16C	0.96
C2—C3	1.3753 (18)	C17—H17A	0.96
C2—H2	0.93	C17—H17B	0.96
C3—C4	1.395 (2)	C17—H17C	0.96
C4—C5	1.377 (2)	C18—H18A	0.96
C4—H4	0.93	C18—H18B	0.96
C5—C6	1.4270 (18)	C18—H18C	0.96
C6—C7	1.4641 (19)	C19—H19A	0.96
C7—C8	1.4603 (19)	C19—H19B	0.96
C8—C9	1.3526 (18)	C19—H19C	0.96
C9—C10	1.4740 (18)

C9—O1—C1	121.22 (10)	C10—C11—H11	118.8
C5—O3—C17	117.68 (12)	C13—C12—C11	119.26 (13)
C3—O4—C16	117.79 (11)	C13—C12—H12	120.4
C8—O5—C18	115.26 (12)	C11—C12—H12	120.4
C13—O6—C19	118.35 (12)	O6—C13—C14	115.45 (12)
O1—C1—C6	122.08 (12)	O6—C13—C12	125.06 (13)
O1—C1—C2	113.58 (11)	C14—C13—C12	119.50 (12)
C6—C1—C2	124.33 (12)	C15—C14—C13	120.90 (13)
C3—C2—C1	117.38 (12)	C15—C14—H14	119.6
C3—C2—H2	121.3	C13—C14—H14	119.6
C1—C2—H2	121.3	C14—C15—C10	121.25 (13)
O4—C3—C2	124.15 (13)	C14—C15—H15	119.4
O4—C3—C4	114.65 (12)	C10—C15—H15	119.4
C2—C3—C4	121.20 (13)	O4—C16—H16A	109.5
C5—C4—C3	120.26 (12)	O4—C16—H16B	109.5
C5—C4—H4	119.9	H16A—C16—H16B	109.5
C3—C4—H4	119.9	O4—C16—H16C	109.5
O3—C5—C4	123.43 (12)	H16A—C16—H16C	109.5
O3—C5—C6	115.93 (12)	H16B—C16—H16C	109.5
C4—C5—C6	120.63 (12)	O3—C17—H17A	109.5
C1—C6—C5	116.09 (12)	O3—C17—H17B	109.5
C1—C6—C7	119.08 (12)	H17A—C17—H17B	109.5
C5—C6—C7	124.77 (12)	O3—C17—H17C	109.5
O2—C7—C8	120.11 (13)	H17A—C17—H17C	109.5
O2—C7—C6	125.17 (13)	H17B—C17—H17C	109.5
C8—C7—C6	114.71 (11)	O5—C18—H18A	109.5
C9—C8—O5	119.91 (11)	O5—C18—H18B	109.5
C9—C8—C7	123.11 (12)	H18A—C18—H18B	109.5
O5—C8—C7	116.87 (11)	O5—C18—H18C	109.5
C8—C9—O1	119.68 (11)	H18A—C18—H18C	109.5
C8—C9—C10	129.53 (12)	H18B—C18—H18C	109.5
O1—C9—C10	110.79 (10)	O6—C19—H19A	109.5
C11—C10—C15	116.66 (12)	O6—C19—H19B	109.5
C11—C10—C9	120.31 (12)	H19A—C19—H19B	109.5
C15—C10—C9	123.02 (12)	O6—C19—H19C	109.5
C12—C11—C10	122.43 (13)	H19A—C19—H19C	109.5
C12—C11—H11	118.8	H19B—C19—H19C	109.5

C9—O1—C1—C6	3.33 (19)	C18—O5—C8—C7	−72.50 (18)
C9—O1—C1—C2	−175.58 (12)	O2—C7—C8—C9	179.37 (14)
O1—C1—C2—C3	178.92 (12)	C6—C7—C8—C9	0.6 (2)
C6—C1—C2—C3	0.0 (2)	O2—C7—C8—O5	3.1 (2)
C16—O4—C3—C2	3.0 (2)	C6—C7—C8—O5	−175.74 (11)
C16—O4—C3—C4	−177.12 (14)	O5—C8—C9—O1	174.86 (11)
C1—C2—C3—O4	−177.39 (13)	C7—C8—C9—O1	−1.3 (2)
C1—C2—C3—C4	2.8 (2)	O5—C8—C9—C10	−4.9 (2)
O4—C3—C4—C5	177.35 (12)	C7—C8—C9—C10	178.90 (13)
C2—C3—C4—C5	−2.8 (2)	C1—O1—C9—C8	−0.58 (19)
C17—O3—C5—C4	0.4 (2)	C1—O1—C9—C10	179.24 (11)
C17—O3—C5—C6	−179.72 (13)	C8—C9—C10—C11	−171.67 (14)
C3—C4—C5—O3	179.81 (12)	O1—C9—C10—C11	8.53 (18)
C3—C4—C5—C6	0.0 (2)	C8—C9—C10—C15	9.3 (2)
O1—C1—C6—C5	178.53 (12)	O1—C9—C10—C15	−170.51 (13)
C2—C1—C6—C5	−2.7 (2)	C15—C10—C11—C12	0.1 (2)
O1—C1—C6—C7	−4.0 (2)	C9—C10—C11—C12	−178.98 (13)
C2—C1—C6—C7	174.78 (13)	C10—C11—C12—C13	0.2 (2)
O3—C5—C6—C1	−177.23 (12)	C19—O6—C13—C14	164.09 (15)
C4—C5—C6—C1	2.63 (19)	C19—O6—C13—C12	−15.9 (2)
O3—C5—C6—C7	5.5 (2)	C11—C12—C13—O6	179.50 (14)
C4—C5—C6—C7	−174.66 (13)	C11—C12—C13—C14	−0.4 (2)
C1—C6—C7—O2	−176.71 (14)	O6—C13—C14—C15	−179.64 (14)
C5—C6—C7—O2	0.5 (2)	C12—C13—C14—C15	0.3 (2)
C1—C6—C7—C8	2.05 (19)	C13—C14—C15—C10	0.0 (3)
C5—C6—C7—C8	179.26 (12)	C11—C10—C15—C14	−0.3 (2)
C18—O5—C8—C9	111.09 (17)	C9—C10—C15—C14	178.81 (14)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C15—H15···O5	0.93	2.23	2.8690 (18)	126
C17—H17B···O2ⁱ	0.96	2.48	3.2674 (19)	139
C17—H17B···O3ⁱ	0.96	2.61	3.458 (2)	148
C18—H18B···O6ⁱⁱ	0.96	2.57	3.530 (2)	173
C19—H19C···O5ⁱⁱⁱ	0.96	2.51	3.457 (2)	170

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

Experimental details

Crystal data
Chemical formula	C₁₉H₁₈O₆
M_r	342.33
Crystal system, space group	Triclinic, P1
Temperature (K)	298
a, b, c (Å)	8.7854 (3), 9.2743 (4), 10.6950 (4)
α, β, γ (°)	70.749 (1), 81.448 (1), 83.078 (1)
V (Å³)	811.15 (5)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.11
Crystal size (mm)	0.40 × 0.22 × 0.18

Data collection
Diffractometer	Bruker SMART APEXII CCD area-detector
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.839, 0.946
No. of measured, independent and observed [I > 2σ(I)] reflections	5901, 3930, 2827
R_int	0.023
(sin θ/λ)_max (Å⁻¹)	0.667

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.044, 0.131, 1.06
No. of reflections	3930
No. of parameters	230
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.23, −0.19

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al. 2006)..

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C15—H15···O5	0.93	2.23	2.8690 (18)	126
C17—H17B···O2ⁱ	0.96	2.48	3.2674 (19)	139
C17—H17B···O3ⁱ	0.96	2.61	3.458 (2)	148
C18—H18B···O6ⁱⁱ	0.96	2.57	3.530 (2)	173
C19—H19C···O5ⁱⁱⁱ	0.96	2.51	3.457 (2)	170

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

Acknowledgements

This work was supported by the Department of Chemistry and Research Funds from the Faculty of Science, Chulalongkorn University to TA and by the Thailand Research Fund and the Commission on Higher Education (grant No. MRG4980018) to PS.

References

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