4-(4-Methoxy­phen­yl)-7,7-dimethyl-5-oxo-5,6,7,8-tetra­hydrochromene-2,5-dione

Shi, H.

doi:10.1107/S160053680904971X

organic compounds

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ISSN: 2056-9890

Volume 65| Part 12| December 2009| Page o3216

doi:10.1107/S160053680904971X

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4-(4-Methoxyphenyl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydrochromene-2,5-dione

Hao Shi ^a ^*

^aThe College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
^*Correspondence e-mail: shihao@zjut.edu.cn

(Received 16 November 2009; accepted 19 November 2009; online 25 November 2009)

The title compound, C₁₈H₂₀O₄, was synthesized by the reaction of 4-methoxybenzaldehyde, 2,2-dimethyl-1,3-dioxane-4,6-dione and 5,5-dimethylcyclohexane-1,3-dione with triethylbenzylammonium chloride in water as a green solvent. In the molecule of the title compound, the six-membered pyranone ring of the hexahydrocoumarin system has a screw-boat conformation while that of the dimethylcyclohexenone system has a distorted envelope conformation. The CMe₂ portion of this ring is disordered over two positions with refined occupancies of 0.721 (7) and 0.279 (7).

Related literature

For background to the applications of coumarin derivatives see: Wang et al. (1999 ); Yang (2001 ). For ring puckering parameters, see: Cremer & Pople (1975 ).

Experimental

Crystal data

C₁₈H₂₀O₄
M_r = 300.34
Orthorhombic, P 2₁ 2₁ 2₁
a = 5.9793 (6) Å
b = 11.7371 (12) Å
c = 22.565 (2) Å
V = 1583.6 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 298 K
0.37 × 0.21 × 0.17 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1999 ) T_min = 0.968, T_max = 0.985
7934 measured reflections
1643 independent reflections
1288 reflections with I > 2σ(I)
R_int = 0.075

Refinement

R[F² > 2σ(F²)] = 0.046
wR(F²) = 0.128
S = 1.05
1643 reflections
233 parameters
H-atom parameters constrained
Δρ_max = 0.28 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680904971X/sj2689sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053680904971X/sj2689Isup2.hkl

checkCIF report

Comment top

Coumarin is an important chemical with unique characteristics. It is widely used in hand soaps, detergents, lotions and laser dyes (Wang et al., 1999). Coumarin and some of its derivatives have been tested in pharmacology for treatment of HIV (Yang, 2001). To obtain a coumarin in a more environmentally friendly way, water was used as a green solvent in the synthesis of the title compound.

In the molecule of the title compound, the two six membered rings of the hexahydrocoumarin system are not planar, the cyclohexene ring A (O1/C1–C4/C9) adopts the screw-boat conformation with puckering parameters (Cremer & Pople, 1975) Q= 0.468 (5) Å, θ= 64.4 (5)° and ϕ = 143.5 (6)°; for the ring B (C4–C9), disorder was modelled for the C6, C10, C11 atoms resolved over two positions with occupancies of 0.721 (7) and 0.279 (7). Ring C (C12–C17) is, of course, planar. The dihedral angle between the least-squares plane of ring A(O1/C1–C4/C9) and that of ring C (C12–C17) is 87.59 (12)°.

Related literature top

For background to the applications of coumarin derivatives see: Wang et al. (1999); Yang (2001). For ring puckering parameters, see: Cremer & Pople (1975).

Experimental top

A mixture of 4-methoxybenzaldehyde (100 mmol), 5,5-dimethyl-1,3-cyclohexanedione (100 mmol), 2,2-dimethyl-1,3-dioxane-4,6-dione (100 mmol), triethylbenzylammonium chloride(TEBA) (15 mmol) and 400 mL of water was stirred at 65°C for 4 h (Fig.2). The reaction mixture was cooled to room temperature, the precipitated product was filtered and recrystallized from ethanol to give the title compound. Crystals suitable for X-ray structure analysis were obtained by slow evaporation from methanol solution at room temperature.

Computing details top

Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. Structure of 1 showing 30% probability displacement ellipsoids and the atom numbering scheme. Bonds to atoms of the minor disorder component are shown as dashed lines.
	Fig. 2. The preparation of the title compound.

4-(4-Methoxyphenyl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydrochromene-2,5-dione top

Crystal data top

C₁₈H₂₀O₄	F(000) = 640
M_r = 300.34	D_x = 1.260 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 2932 reflections
a = 5.9793 (6) Å	θ = 2.5–25.3°
b = 11.7371 (12) Å	µ = 0.09 mm⁻¹
c = 22.565 (2) Å	T = 298 K
V = 1583.6 (3) Å³	Prism, colorless
Z = 4	0.37 × 0.21 × 0.17 mm

Data collection top

Bruker SMART CCD area-detector diffractometer	1643 independent reflections
Radiation source: fine-focus sealed tube	1288 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.075
ϕ and ω scans	θ_max = 25.0°, θ_min = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 1999)	h = −7→6
T_min = 0.968, T_max = 0.985	k = −13→10
7934 measured reflections	l = −25→26

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)] = 0.046	H-atom parameters constrained
wR(F²) = 0.128	w = 1/[σ²(F_o²) + (0.0461P)² + 0.553P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max = 0.001
1643 reflections	Δρ_max = 0.28 e Å⁻³
233 parameters	Δρ_min = −0.26 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.031 (4)

Crystal data top

C₁₈H₂₀O₄	V = 1583.6 (3) Å³
M_r = 300.34	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 5.9793 (6) Å	µ = 0.09 mm⁻¹
b = 11.7371 (12) Å	T = 298 K
c = 22.565 (2) Å	0.37 × 0.21 × 0.17 mm

Data collection top

Bruker SMART CCD area-detector diffractometer	1643 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 1999)	1288 reflections with I > 2σ(I)
T_min = 0.968, T_max = 0.985	R_int = 0.075
7934 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.046	0 restraints
wR(F²) = 0.128	H-atom parameters constrained
S = 1.05	Δρ_max = 0.28 e Å⁻³
1643 reflections	Δρ_min = −0.26 e Å⁻³
233 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	Occ. (<1)
O1	0.2602 (5)	0.1771 (2)	0.05280 (10)	0.0674 (8)
O2	0.1786 (9)	0.0959 (3)	−0.03152 (13)	0.1292 (18)
O3	0.8756 (6)	0.0717 (3)	0.17213 (14)	0.0865 (10)
O4	0.2049 (6)	−0.4043 (2)	0.11499 (12)	0.0742 (9)
C1	0.3211 (11)	0.1093 (3)	0.00511 (16)	0.0782 (15)
C2	0.5491 (10)	0.0631 (4)	0.00509 (16)	0.0766 (15)
H2A	0.6523	0.1218	−0.0079	0.092*
H2B	0.5577	0.0005	−0.0229	0.092*
C3	0.6193 (8)	0.0208 (3)	0.06653 (15)	0.0596 (10)
H3	0.7809	0.0069	0.0657	0.072*
C4	0.5755 (7)	0.1163 (3)	0.10917 (15)	0.0498 (9)
C5	0.7227 (8)	0.1351 (4)	0.1596 (2)	0.0757 (13)
C6	0.7088 (10)	0.2528 (4)	0.1872 (2)	0.0597 (17)	0.721 (7)
H6A	0.7831	0.3072	0.1616	0.072*	0.721 (7)
H6B	0.7866	0.2523	0.2249	0.072*	0.721 (7)
C6'	0.584 (3)	0.1803 (12)	0.2150 (6)	0.064 (5)	0.279 (7)
H6'1	0.4749	0.1236	0.2271	0.077*	0.279 (7)
H6'2	0.6836	0.1945	0.2481	0.077*	0.279 (7)
C7	0.4652 (6)	0.2907 (3)	0.19705 (14)	0.0516 (9)
C8	0.3415 (7)	0.2858 (3)	0.13786 (14)	0.0591 (10)
H8A	0.1821	0.2814	0.1455	0.071*
H8B	0.3695	0.3559	0.1163	0.071*
C9	0.4070 (7)	0.1883 (3)	0.10012 (13)	0.0502 (9)
C10	0.3528 (11)	0.2039 (5)	0.2381 (2)	0.0695 (19)	0.721 (7)
H10A	0.4307	0.2017	0.2753	0.104*	0.721 (7)
H10B	0.3571	0.1299	0.2201	0.104*	0.721 (7)
H10C	0.2001	0.2258	0.2447	0.104*	0.721 (7)
C11	0.4615 (15)	0.4084 (6)	0.2232 (3)	0.080 (2)	0.721 (7)
H11A	0.5441	0.4088	0.2597	0.119*	0.721 (7)
H11B	0.3097	0.4307	0.2308	0.119*	0.721 (7)
H11C	0.5286	0.4611	0.1959	0.119*	0.721 (7)
C10'	0.651 (3)	0.3774 (11)	0.1822 (7)	0.062 (4)	0.279 (7)
H10D	0.5839	0.4465	0.1678	0.094*	0.279 (7)
H10E	0.7469	0.3463	0.1522	0.094*	0.279 (7)
H10F	0.7361	0.3934	0.2172	0.094*	0.279 (7)
C11'	0.326 (4)	0.3516 (15)	0.2465 (7)	0.073 (5)	0.279 (7)
H11D	0.4237	0.3733	0.2783	0.109*	0.279 (7)
H11E	0.2137	0.3005	0.2612	0.109*	0.279 (7)
H11F	0.2560	0.4182	0.2303	0.109*	0.279 (7)
C12	0.5050 (7)	−0.0900 (3)	0.08200 (13)	0.0496 (9)
C13	0.3053 (7)	−0.0949 (3)	0.11313 (14)	0.0522 (9)
H13	0.2407	−0.0275	0.1263	0.063*
C14	0.1992 (7)	−0.1971 (3)	0.12516 (14)	0.0545 (9)
H14	0.0657	−0.1980	0.1463	0.065*
C15	0.2929 (7)	−0.2976 (3)	0.10557 (15)	0.0533 (9)
C16	0.4910 (7)	−0.2948 (3)	0.07371 (15)	0.0595 (10)
H16	0.5539	−0.3623	0.0601	0.071*
C17	0.5949 (7)	−0.1928 (3)	0.06213 (14)	0.0570 (9)
H17	0.7277	−0.1922	0.0406	0.068*
C18	0.0106 (9)	−0.4122 (4)	0.1497 (2)	0.0809 (13)
H18A	0.0434	−0.3882	0.1895	0.121*
H18B	−0.0408	−0.4897	0.1502	0.121*
H18C	−0.1035	−0.3641	0.1333	0.121*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.094 (2)	0.0597 (15)	0.0483 (13)	0.0106 (16)	−0.0219 (15)	0.0002 (11)
O2	0.216 (5)	0.103 (2)	0.0688 (18)	0.026 (3)	−0.067 (3)	−0.0170 (18)
O3	0.071 (2)	0.0778 (19)	0.110 (2)	0.0202 (19)	−0.0248 (19)	−0.0096 (18)
O4	0.090 (2)	0.0495 (15)	0.0830 (18)	−0.0081 (17)	0.0002 (19)	−0.0120 (13)
C1	0.139 (5)	0.058 (2)	0.0377 (18)	0.008 (3)	−0.018 (3)	0.0036 (17)
C2	0.124 (4)	0.061 (2)	0.045 (2)	0.003 (3)	0.016 (3)	0.0031 (18)
C3	0.073 (3)	0.053 (2)	0.0527 (19)	0.003 (2)	0.010 (2)	−0.0003 (16)
C4	0.056 (2)	0.0419 (17)	0.0511 (18)	−0.0029 (18)	0.0013 (18)	0.0013 (14)
C5	0.067 (3)	0.069 (3)	0.092 (3)	0.020 (3)	−0.025 (3)	−0.019 (2)
C6	0.061 (4)	0.057 (3)	0.061 (3)	−0.004 (3)	−0.006 (3)	−0.005 (2)
C6'	0.077 (11)	0.058 (8)	0.057 (8)	−0.006 (9)	−0.015 (8)	0.006 (6)
C7	0.058 (2)	0.052 (2)	0.0456 (18)	−0.002 (2)	−0.0049 (17)	−0.0024 (15)
C8	0.072 (3)	0.0501 (19)	0.0554 (19)	0.009 (2)	−0.010 (2)	−0.0061 (16)
C9	0.065 (2)	0.0471 (17)	0.0381 (16)	−0.002 (2)	−0.0074 (18)	0.0046 (14)
C10	0.083 (5)	0.082 (4)	0.044 (3)	0.000 (4)	0.001 (3)	0.011 (3)
C11	0.097 (6)	0.071 (4)	0.071 (4)	0.009 (4)	−0.022 (4)	−0.019 (3)
C10'	0.063 (9)	0.055 (8)	0.069 (8)	−0.007 (8)	0.002 (8)	−0.008 (7)
C11'	0.084 (13)	0.074 (10)	0.061 (9)	0.006 (10)	−0.007 (9)	−0.016 (8)
C12	0.062 (2)	0.0481 (19)	0.0382 (16)	0.0058 (19)	−0.0006 (17)	−0.0007 (14)
C13	0.063 (2)	0.0440 (18)	0.0500 (18)	0.0108 (19)	0.0036 (19)	−0.0043 (15)
C14	0.059 (2)	0.053 (2)	0.0510 (18)	0.005 (2)	0.0000 (19)	−0.0069 (16)
C15	0.064 (2)	0.0478 (19)	0.0477 (17)	0.000 (2)	−0.0131 (19)	−0.0059 (15)
C16	0.072 (3)	0.050 (2)	0.057 (2)	0.013 (2)	−0.002 (2)	−0.0141 (17)
C17	0.064 (2)	0.057 (2)	0.0498 (19)	0.007 (2)	0.0061 (19)	−0.0057 (16)
C18	0.083 (3)	0.061 (2)	0.099 (3)	−0.014 (3)	−0.002 (3)	0.003 (2)

Geometric parameters (Å, º) top

O1—C1	1.387 (5)	C8—C9	1.479 (5)
O1—C9	1.388 (4)	C8—H8A	0.9700
O2—C1	1.197 (6)	C8—H8B	0.9700
O3—C5	1.213 (5)	C10—H10A	0.9600
O4—C15	1.376 (4)	C10—H10B	0.9600
O4—C18	1.404 (6)	C10—H10C	0.9600
C1—C2	1.467 (7)	C11—H11A	0.9600
C2—C3	1.531 (5)	C11—H11B	0.9600
C2—H2A	0.9700	C11—H11C	0.9600
C2—H2B	0.9700	C10'—H10D	0.9600
C3—C4	1.500 (5)	C10'—H10E	0.9600
C3—C12	1.510 (5)	C10'—H10F	0.9600
C3—H3	0.9800	C11'—H11D	0.9600
C4—C9	1.331 (5)	C11'—H11E	0.9600
C4—C5	1.455 (5)	C11'—H11F	0.9600
C5—C6	1.517 (6)	C12—C13	1.386 (5)
C5—C6'	1.592 (16)	C12—C17	1.395 (5)
C6—C7	1.539 (7)	C13—C14	1.383 (5)
C6—H6A	0.9700	C13—H13	0.9300
C6—H6B	0.9700	C14—C15	1.379 (5)
C6'—C7	1.532 (15)	C14—H14	0.9300
C6'—H6'1	0.9700	C15—C16	1.386 (6)
C6'—H6'2	0.9700	C16—C17	1.374 (5)
C7—C11	1.503 (7)	C16—H16	0.9300
C7—C8	1.528 (5)	C17—H17	0.9300
C7—C10	1.533 (6)	C18—H18A	0.9600
C7—C10'	1.542 (14)	C18—H18B	0.9600
C7—C11'	1.564 (16)	C18—H18C	0.9600

C1—O1—C9	119.0 (3)	C6'—C7—C11'	116.4 (9)
C15—O4—C18	117.6 (3)	C10—C7—C11'	68.8 (8)
O2—C1—O1	115.1 (5)	C6—C7—C11'	137.5 (8)
O2—C1—C2	127.8 (4)	C10'—C7—C11'	103.6 (10)
O1—C1—C2	117.1 (4)	C9—C8—C7	113.8 (3)
C1—C2—C3	112.0 (4)	C9—C8—H8A	108.8
C1—C2—H2A	109.2	C7—C8—H8A	108.8
C3—C2—H2A	109.2	C9—C8—H8B	108.8
C1—C2—H2B	109.2	C7—C8—H8B	108.8
C3—C2—H2B	109.2	H8A—C8—H8B	107.7
H2A—C2—H2B	107.9	C4—C9—O1	122.4 (3)
C4—C3—C12	114.6 (3)	C4—C9—C8	127.1 (3)
C4—C3—C2	106.9 (3)	O1—C9—C8	110.4 (3)
C12—C3—C2	111.4 (3)	C7—C10—H10A	109.5
C4—C3—H3	107.9	C7—C10—H10B	109.5
C12—C3—H3	107.9	C7—C10—H10C	109.5
C2—C3—H3	107.9	C7—C11—H11A	109.5
C9—C4—C5	118.8 (3)	C7—C11—H11B	109.5
C9—C4—C3	120.5 (3)	C7—C11—H11C	109.5
C5—C4—C3	120.6 (3)	C7—C10'—H10D	109.5
O3—C5—C4	123.0 (4)	C7—C10'—H10E	109.5
O3—C5—C6	120.3 (4)	H10D—C10'—H10E	109.5
C4—C5—C6	115.2 (4)	C7—C10'—H10F	109.5
O3—C5—C6'	114.5 (6)	H10D—C10'—H10F	109.5
C4—C5—C6'	110.5 (6)	H10E—C10'—H10F	109.5
C6—C5—C6'	49.1 (6)	C7—C11'—H11D	109.5
C5—C6—C7	112.0 (4)	C7—C11'—H11E	109.5
C5—C6—H6A	109.2	H11D—C11'—H11E	109.5
C7—C6—H6A	109.2	C7—C11'—H11F	109.5
C5—C6—H6B	109.2	H11D—C11'—H11F	109.5
C7—C6—H6B	109.2	H11E—C11'—H11F	109.5
H6A—C6—H6B	107.9	C13—C12—C17	117.3 (3)
C7—C6'—C5	108.4 (8)	C13—C12—C3	122.9 (3)
C7—C6'—H6'1	110.0	C17—C12—C3	119.7 (3)
C5—C6'—H6'1	110.0	C14—C13—C12	122.0 (3)
C7—C6'—H6'2	110.0	C14—C13—H13	119.0
C5—C6'—H6'2	110.0	C12—C13—H13	119.0
H6'1—C6'—H6'2	108.4	C15—C14—C13	119.5 (3)
C11—C7—C8	111.8 (4)	C15—C14—H14	120.3
C11—C7—C6'	132.9 (6)	C13—C14—H14	120.3
C8—C7—C6'	115.1 (6)	O4—C15—C14	125.0 (4)
C11—C7—C10	111.5 (5)	O4—C15—C16	115.4 (3)
C8—C7—C10	106.9 (4)	C14—C15—C16	119.6 (4)
C6'—C7—C10	58.7 (7)	C17—C16—C15	120.4 (3)
C11—C7—C6	109.7 (5)	C17—C16—H16	119.8
C8—C7—C6	108.8 (3)	C15—C16—H16	119.8
C6'—C7—C6	49.8 (7)	C16—C17—C12	121.2 (4)
C10—C7—C6	108.1 (4)	C16—C17—H17	119.4
C11—C7—C10'	59.3 (6)	C12—C17—H17	119.4
C8—C7—C10'	100.5 (6)	O4—C18—H18A	109.5
C6'—C7—C10'	106.5 (9)	O4—C18—H18B	109.5
C10—C7—C10'	152.4 (7)	H18A—C18—H18B	109.5
C6—C7—C10'	58.6 (6)	O4—C18—H18C	109.5
C11—C7—C11'	44.9 (7)	H18A—C18—H18C	109.5
C8—C7—C11'	112.5 (7)	H18B—C18—H18C	109.5

C9—O1—C1—O2	173.9 (4)	C5—C6—C7—C10'	−147.4 (8)
C9—O1—C1—C2	−6.4 (5)	C5—C6—C7—C11'	137.6 (12)
O2—C1—C2—C3	−138.4 (5)	C11—C7—C8—C9	158.7 (5)
O1—C1—C2—C3	41.9 (5)	C6'—C7—C8—C9	−16.1 (8)
C1—C2—C3—C4	−51.9 (5)	C10—C7—C8—C9	−79.0 (5)
C1—C2—C3—C12	73.9 (4)	C6—C7—C8—C9	37.5 (5)
C12—C3—C4—C9	−92.1 (4)	C10'—C7—C8—C9	97.7 (6)
C2—C3—C4—C9	31.8 (5)	C11'—C7—C8—C9	−152.6 (9)
C12—C3—C4—C5	90.9 (5)	C5—C4—C9—O1	179.4 (4)
C2—C3—C4—C5	−145.2 (4)	C3—C4—C9—O1	2.3 (5)
C9—C4—C5—O3	177.6 (4)	C5—C4—C9—C8	−3.2 (6)
C3—C4—C5—O3	−5.3 (7)	C3—C4—C9—C8	179.7 (4)
C9—C4—C5—C6	−16.1 (6)	C1—O1—C9—C4	−17.4 (5)
C3—C4—C5—C6	161.0 (4)	C1—O1—C9—C8	164.8 (3)
C9—C4—C5—C6'	37.3 (7)	C7—C8—C9—C4	−8.8 (5)
C3—C4—C5—C6'	−145.6 (6)	C7—C8—C9—O1	168.8 (3)
O3—C5—C6—C7	−146.6 (5)	C4—C3—C12—C13	28.7 (5)
C4—C5—C6—C7	46.7 (6)	C2—C3—C12—C13	−92.8 (4)
C6'—C5—C6—C7	−49.2 (8)	C4—C3—C12—C17	−154.6 (3)
O3—C5—C6'—C7	157.8 (7)	C2—C3—C12—C17	83.9 (4)
C4—C5—C6'—C7	−58.2 (10)	C17—C12—C13—C14	1.0 (5)
C6—C5—C6'—C7	48.0 (7)	C3—C12—C13—C14	177.8 (3)
C5—C6'—C7—C11	−125.9 (8)	C12—C13—C14—C15	−0.3 (5)
C5—C6'—C7—C8	47.5 (11)	C18—O4—C15—C14	−3.3 (5)
C5—C6'—C7—C10	142.8 (11)	C18—O4—C15—C16	176.7 (3)
C5—C6'—C7—C6	−46.5 (7)	C13—C14—C15—O4	179.5 (3)
C5—C6'—C7—C10'	−62.9 (11)	C13—C14—C15—C16	−0.5 (5)
C5—C6'—C7—C11'	−177.7 (10)	O4—C15—C16—C17	−179.4 (3)
C5—C6—C7—C11	−178.8 (4)	C14—C15—C16—C17	0.6 (5)
C5—C6—C7—C8	−56.3 (5)	C15—C16—C17—C12	0.1 (6)
C5—C6—C7—C6'	51.1 (7)	C13—C12—C17—C16	−0.9 (5)
C5—C6—C7—C10	59.4 (5)	C3—C12—C17—C16	−177.8 (4)

Experimental details

Crystal data
Chemical formula	C₁₈H₂₀O₄
M_r	300.34
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	298
a, b, c (Å)	5.9793 (6), 11.7371 (12), 22.565 (2)
V (Å³)	1583.6 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.37 × 0.21 × 0.17

Data collection
Diffractometer	Bruker SMART CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 1999)
T_min, T_max	0.968, 0.985
No. of measured, independent and observed [I > 2σ(I)] reflections	7934, 1643, 1288
R_int	0.075
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.046, 0.128, 1.05
No. of reflections	1643
No. of parameters	233
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.28, −0.26

Computer programs: SMART (Bruker, 1999), SAINT (Bruker, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997).

Acknowledgements

The research was supported by the Open Foundation of Key Disciplines within the Zhejiang Provincial Key Disciplines.

References

Bruker (1999). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. 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
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Wang, X. F., Qu, Y. & Gu, F. (1999). Speciality Petrochem. 1, 49–52. Google Scholar
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