Arctigenin: a lignan from Arctium lappa.

The title compound {systematic name: (3R-trans)-4-[(3,4-dimethoxy-phen-yl)meth-yl]-3-[(4-hydr-oxy-3-methoxy-phen-yl)meth-yl]-4,5-dihydrofuran-2(3H)-one}, C(21)H(24)O(6), has a dibenz-yl-butyrolactone skeleton. The two aromatic rings are inclined at a dihedral angle of 68.75 (7)° with respect to each other. The lactone ring adopts an envelope conformation. A series of O-H⋯O and C-H⋯O hydrogen bonds contribute to the stabilization of the crystal packing. The absolute configuration was assigned on the basis of the published literature.

Related literature

For related literature, see: Awale et al. (2006 ▶). For a similar structure, see: Bruno-Colmenárez et al. (2007 ▶).

Experimental

Crystal data

C21H24O6

M = 372.40

Orthorhombic,

a = 9.4845 (19) Å

b = 10.065 (2) Å

c = 19.915 (4) Å

V = 1901.2 (7) Å3

Z = 4

Mo Kα radiation

μ = 0.10 mm−1

T = 113 (2) K

0.14 × 0.12 × 0.10 mm

Data collection

Rigaku Saturn CCD area-detector diffractometer

Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005 ▶) T min = 0.987, T max = 0.991

13910 measured reflections

2581 independent reflections

2449 reflections with I > 2σ(I)

R int = 0.037

Refinement

R[F 2 > 2σ(F 2)] = 0.032

wR(F 2) = 0.079

S = 1.06

2581 reflections

251 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.20 e Å−3

Δρmin = −0.15 e Å−3

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: CrystalStructure (Rigaku/MSC, 2005 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808021752/bt2739sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808021752/bt2739Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C21H24O6	F000 = 792
Mr = 372.40	Dx = 1.301 Mg m−3
Orthorhombic, P212121	Mo Kα radiation λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 5995 reflections
a = 9.4845 (19) Å	θ = 2.3–27.9º
b = 10.065 (2) Å	µ = 0.10 mm−1
c = 19.915 (4) Å	T = 113 (2) K
V = 1901.2 (7) Å3	Block, colourless
Z = 4	0.14 × 0.12 × 0.10 mm

Rigaku Saturn CCD area-detector diffractometer	2581 independent reflections
Radiation source: rotating anode	2449 reflections with I > 2σ(I)
Monochromator: confocal	Rint = 0.037
Detector resolution: 7.31 pixels mm-1	θmax = 27.8º
T = 113(2) K	θmin = 2.1º
ω scans	h = −12→12
Absorption correction: multi-scan(CrystalClear; Rigaku/MSC, 2005)	k = −11→13
Tmin = 0.987, Tmax = 0.991	l = −26→16
13910 measured reflections

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.032	w = 1/[σ2(Fo2) + (0.0475P)2 + 0.1518P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.079	(Δ/σ)max = 0.001
S = 1.06	Δρmax = 0.20 e Å−3
2581 reflections	Δρmin = −0.15 e Å−3
251 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.032 (3)
Secondary atom site location: difference Fourier map

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.

	x	y	z	Uiso*/Ueq
O1	0.07380 (13)	0.28900 (13)	0.73971 (6)	0.0287 (3)
O2	0.23820 (12)	0.17843 (12)	0.82576 (5)	0.0228 (3)
O3	0.38552 (14)	0.79457 (13)	0.92594 (6)	0.0329 (3)
O4	0.34335 (15)	0.69713 (14)	1.02429 (6)	0.0362 (3)
O5	0.96166 (13)	0.15373 (12)	0.87738 (6)	0.0226 (3)
H5	1.036 (2)	0.195 (2)	0.8592 (10)	0.034*
O6	1.04322 (12)	0.40766 (12)	0.88872 (6)	0.0241 (3)
C1	0.44649 (17)	0.48348 (17)	0.79244 (7)	0.0196 (3)
C2	0.35798 (18)	0.53926 (18)	0.74441 (8)	0.0230 (3)
H2	0.3827	0.6219	0.7246	0.028*
C3	0.23339 (18)	0.47622 (18)	0.72471 (8)	0.0247 (4)
H3	0.1747	0.5159	0.6917	0.030*
C4	0.19554 (17)	0.35649 (18)	0.75310 (8)	0.0226 (3)
C5	0.28519 (17)	0.29699 (17)	0.80056 (7)	0.0196 (3)
C6	0.40879 (17)	0.35955 (17)	0.81937 (7)	0.0192 (3)
H6	0.4693	0.3180	0.8511	0.023*
C7	−0.0319 (2)	0.3594 (2)	0.70329 (11)	0.0412 (5)
H7A	−0.0003	0.3730	0.6569	0.062*
H7B	−0.0485	0.4458	0.7246	0.062*
H7C	−0.1196	0.3079	0.7033	0.062*
C8	0.32263 (19)	0.11735 (19)	0.87673 (9)	0.0276 (4)
H8A	0.3305	0.1774	0.9153	0.041*
H8B	0.4168	0.0988	0.8588	0.041*
H8C	0.2784	0.0340	0.8910	0.041*
C9	0.57710 (16)	0.55340 (17)	0.81719 (7)	0.0209 (3)
H9A	0.6165	0.6068	0.7799	0.025*
H9B	0.6482	0.4855	0.8294	0.025*
C10	0.55425 (17)	0.64553 (16)	0.87818 (8)	0.0213 (3)
H10	0.6479	0.6827	0.8916	0.026*
C11	0.4557 (2)	0.76166 (18)	0.86314 (9)	0.0287 (4)
H11A	0.5100	0.8389	0.8464	0.034*
H11B	0.3856	0.7361	0.8286	0.034*
C12	0.39834 (18)	0.69247 (18)	0.96988 (8)	0.0257 (4)
C13	0.48662 (16)	0.58224 (16)	0.94058 (8)	0.0192 (3)
H13	0.4229	0.5086	0.9259	0.023*
C14	0.58852 (17)	0.52865 (17)	0.99399 (7)	0.0211 (3)
H14A	0.6435	0.6035	1.0129	0.025*
H14B	0.5334	0.4884	1.0310	0.025*
C15	0.68864 (17)	0.42650 (16)	0.96613 (8)	0.0194 (3)
C16	0.65324 (16)	0.29296 (17)	0.96147 (7)	0.0205 (3)
H16	0.5651	0.2633	0.9785	0.025*
C17	0.74541 (16)	0.20166 (17)	0.93208 (7)	0.0206 (3)
H17	0.7201	0.1105	0.9295	0.025*
C18	0.87370 (16)	0.24419 (16)	0.90675 (7)	0.0188 (3)
C19	0.91196 (16)	0.37751 (17)	0.91323 (7)	0.0187 (3)
C20	0.82073 (16)	0.46753 (17)	0.94260 (7)	0.0192 (3)
H20	0.8479	0.5580	0.9469	0.023*
C21	1.08409 (19)	0.54337 (18)	0.89079 (10)	0.0329 (4)
H21A	1.0905	0.5726	0.9376	0.049*
H21B	1.0139	0.5973	0.8671	0.049*
H21C	1.1761	0.5538	0.8691	0.049*

	U11	U22	U33	U12	U13	U23
O1	0.0263 (6)	0.0277 (7)	0.0322 (6)	−0.0037 (6)	−0.0070 (5)	0.0021 (5)
O2	0.0269 (6)	0.0178 (6)	0.0237 (5)	0.0014 (5)	0.0016 (5)	0.0025 (4)
O3	0.0430 (7)	0.0206 (6)	0.0353 (7)	0.0115 (6)	0.0054 (6)	0.0006 (5)
O4	0.0416 (7)	0.0322 (8)	0.0349 (7)	0.0107 (7)	0.0139 (6)	−0.0030 (6)
O5	0.0210 (5)	0.0180 (6)	0.0288 (6)	0.0004 (5)	0.0004 (5)	−0.0031 (5)
O6	0.0187 (5)	0.0194 (6)	0.0342 (6)	−0.0017 (5)	0.0050 (5)	−0.0041 (5)
C1	0.0205 (7)	0.0212 (8)	0.0171 (7)	0.0035 (7)	0.0033 (6)	0.0004 (6)
C2	0.0258 (8)	0.0209 (8)	0.0222 (8)	0.0017 (7)	0.0033 (6)	0.0036 (6)
C3	0.0247 (8)	0.0270 (9)	0.0222 (8)	0.0030 (7)	−0.0030 (6)	0.0041 (7)
C4	0.0225 (7)	0.0241 (9)	0.0214 (7)	0.0008 (7)	−0.0002 (6)	−0.0028 (6)
C5	0.0250 (8)	0.0159 (7)	0.0179 (7)	0.0034 (7)	0.0053 (6)	0.0007 (6)
C6	0.0218 (7)	0.0200 (8)	0.0158 (7)	0.0060 (7)	0.0023 (6)	−0.0002 (6)
C7	0.0310 (10)	0.0340 (11)	0.0584 (12)	−0.0034 (10)	−0.0192 (9)	0.0041 (10)
C8	0.0271 (8)	0.0259 (9)	0.0297 (9)	0.0047 (8)	0.0052 (7)	0.0108 (7)
C9	0.0193 (7)	0.0229 (8)	0.0206 (7)	0.0009 (7)	0.0030 (6)	0.0030 (6)
C10	0.0223 (7)	0.0177 (8)	0.0237 (7)	−0.0003 (7)	0.0015 (6)	0.0014 (6)
C11	0.0358 (9)	0.0193 (8)	0.0308 (9)	0.0049 (8)	0.0032 (7)	0.0029 (7)
C12	0.0250 (8)	0.0215 (8)	0.0307 (8)	0.0035 (7)	0.0022 (7)	−0.0025 (7)
C13	0.0187 (7)	0.0162 (8)	0.0227 (8)	0.0006 (6)	0.0017 (6)	−0.0015 (6)
C14	0.0213 (7)	0.0222 (8)	0.0198 (7)	0.0007 (7)	0.0028 (6)	0.0000 (6)
C15	0.0208 (7)	0.0223 (8)	0.0149 (7)	0.0024 (7)	−0.0018 (6)	0.0008 (6)
C16	0.0192 (7)	0.0220 (8)	0.0204 (7)	−0.0012 (7)	0.0001 (6)	0.0027 (6)
C17	0.0218 (7)	0.0182 (8)	0.0218 (7)	−0.0020 (7)	−0.0035 (6)	0.0019 (6)
C18	0.0193 (7)	0.0182 (8)	0.0190 (7)	0.0037 (6)	−0.0036 (6)	−0.0017 (6)
C19	0.0163 (7)	0.0217 (8)	0.0183 (7)	−0.0010 (6)	−0.0018 (6)	0.0009 (6)
C20	0.0204 (7)	0.0186 (8)	0.0188 (7)	−0.0003 (7)	−0.0023 (6)	−0.0009 (6)
C21	0.0260 (9)	0.0208 (9)	0.0519 (11)	−0.0064 (8)	0.0114 (8)	−0.0055 (8)

O1—C4	1.366 (2)	C9—C10	1.543 (2)
O1—C7	1.426 (2)	C9—H9A	0.9900
O2—C5	1.369 (2)	C9—H9B	0.9900
O2—C8	1.432 (2)	C10—C11	1.526 (2)
O3—C12	1.355 (2)	C10—C13	1.537 (2)
O3—C11	1.455 (2)	C10—H10	1.0000
O4—C12	1.203 (2)	C11—H11A	0.9900
O5—C18	1.3665 (19)	C11—H11B	0.9900
O5—H5	0.90 (2)	C12—C13	1.507 (2)
O6—C19	1.3712 (19)	C13—C14	1.535 (2)
O6—C21	1.421 (2)	C13—H13	1.0000
C1—C2	1.391 (2)	C14—C15	1.506 (2)
C1—C6	1.404 (2)	C14—H14A	0.9900
C1—C9	1.508 (2)	C14—H14B	0.9900
C2—C3	1.398 (2)	C15—C16	1.389 (2)
C2—H2	0.9500	C15—C20	1.400 (2)
C3—C4	1.379 (2)	C16—C17	1.397 (2)
C3—H3	0.9500	C16—H16	0.9500
C4—C5	1.405 (2)	C17—C18	1.385 (2)
C5—C6	1.383 (2)	C17—H17	0.9500
C6—H6	0.9500	C18—C19	1.396 (2)
C7—H7A	0.9800	C19—C20	1.383 (2)
C7—H7B	0.9800	C20—H20	0.9500
C7—H7C	0.9800	C21—H21A	0.9800
C8—H8A	0.9800	C21—H21B	0.9800
C8—H8B	0.9800	C21—H21C	0.9800
C8—H8C	0.9800
C4—O1—C7	116.50 (15)	C9—C10—H10	108.1
C5—O2—C8	116.88 (13)	O3—C11—C10	106.62 (13)
C12—O3—C11	109.96 (13)	O3—C11—H11A	110.4
C18—O5—H5	109.9 (15)	C10—C11—H11A	110.4
C19—O6—C21	116.75 (13)	O3—C11—H11B	110.4
C2—C1—C6	117.88 (16)	C10—C11—H11B	110.4
C2—C1—C9	122.16 (15)	H11A—C11—H11B	108.6
C6—C1—C9	119.94 (14)	O4—C12—O3	120.85 (17)
C1—C2—C3	121.34 (16)	O4—C12—C13	128.17 (17)
C1—C2—H2	119.3	O3—C12—C13	110.98 (13)
C3—C2—H2	119.3	C12—C13—C14	109.88 (13)
C4—C3—C2	120.12 (15)	C12—C13—C10	103.87 (13)
C4—C3—H3	119.9	C14—C13—C10	116.31 (13)
C2—C3—H3	119.9	C12—C13—H13	108.8
O1—C4—C3	125.08 (15)	C14—C13—H13	108.8
O1—C4—C5	115.51 (16)	C10—C13—H13	108.8
C3—C4—C5	119.40 (16)	C15—C14—C13	112.45 (12)
O2—C5—C6	125.01 (14)	C15—C14—H14A	109.1
O2—C5—C4	114.90 (15)	C13—C14—H14A	109.1
C6—C5—C4	120.07 (15)	C15—C14—H14B	109.1
C5—C6—C1	121.14 (15)	C13—C14—H14B	109.1
C5—C6—H6	119.4	H14A—C14—H14B	107.8
C1—C6—H6	119.4	C16—C15—C20	118.66 (15)
O1—C7—H7A	109.5	C16—C15—C14	122.23 (15)
O1—C7—H7B	109.5	C20—C15—C14	119.10 (15)
H7A—C7—H7B	109.5	C15—C16—C17	120.90 (15)
O1—C7—H7C	109.5	C15—C16—H16	119.6
H7A—C7—H7C	109.5	C17—C16—H16	119.6
H7B—C7—H7C	109.5	C18—C17—C16	119.94 (15)
O2—C8—H8A	109.5	C18—C17—H17	120.0
O2—C8—H8B	109.5	C16—C17—H17	120.0
H8A—C8—H8B	109.5	O5—C18—C17	119.10 (15)
O2—C8—H8C	109.5	O5—C18—C19	121.42 (15)
H8A—C8—H8C	109.5	C17—C18—C19	119.46 (15)
H8B—C8—H8C	109.5	O6—C19—C20	125.01 (15)
C1—C9—C10	114.99 (13)	O6—C19—C18	114.57 (14)
C1—C9—H9A	108.5	C20—C19—C18	120.42 (15)
C10—C9—H9A	108.5	C19—C20—C15	120.55 (15)
C1—C9—H9B	108.5	C19—C20—H20	119.7
C10—C9—H9B	108.5	C15—C20—H20	119.7
H9A—C9—H9B	107.5	O6—C21—H21A	109.5
C11—C10—C13	102.73 (13)	O6—C21—H21B	109.5
C11—C10—C9	113.07 (13)	H21A—C21—H21B	109.5
C13—C10—C9	116.48 (13)	O6—C21—H21C	109.5
C11—C10—H10	108.1	H21A—C21—H21C	109.5
C13—C10—H10	108.1	H21B—C21—H21C	109.5
C6—C1—C2—C3	1.7 (2)	O3—C12—C13—C14	137.62 (14)
C9—C1—C2—C3	−176.52 (14)	O4—C12—C13—C10	−167.32 (18)
C1—C2—C3—C4	0.2 (2)	O3—C12—C13—C10	12.54 (18)
C7—O1—C4—C3	−11.9 (2)	C11—C10—C13—C12	−21.56 (16)
C7—O1—C4—C5	167.03 (16)	C9—C10—C13—C12	−145.71 (14)
C2—C3—C4—O1	177.18 (15)	C11—C10—C13—C14	−142.41 (14)
C2—C3—C4—C5	−1.7 (2)	C9—C10—C13—C14	93.44 (17)
C8—O2—C5—C6	1.7 (2)	C12—C13—C14—C15	−174.92 (14)
C8—O2—C5—C4	−176.99 (13)	C10—C13—C14—C15	−57.32 (19)
O1—C4—C5—O2	1.0 (2)	C13—C14—C15—C16	−85.45 (19)
C3—C4—C5—O2	179.99 (14)	C13—C14—C15—C20	93.00 (17)
O1—C4—C5—C6	−177.79 (13)	C20—C15—C16—C17	−1.9 (2)
C3—C4—C5—C6	1.2 (2)	C14—C15—C16—C17	176.52 (14)
O2—C5—C6—C1	−177.86 (14)	C15—C16—C17—C18	−0.4 (2)
C4—C5—C6—C1	0.8 (2)	C16—C17—C18—O5	−179.14 (13)
C2—C1—C6—C5	−2.2 (2)	C16—C17—C18—C19	2.5 (2)
C9—C1—C6—C5	176.05 (13)	C21—O6—C19—C20	−3.5 (2)
C2—C1—C9—C10	89.17 (18)	C21—O6—C19—C18	176.67 (15)
C6—C1—C9—C10	−89.02 (18)	O5—C18—C19—O6	−0.7 (2)
C1—C9—C10—C11	−63.25 (19)	C17—C18—C19—O6	177.63 (13)
C1—C9—C10—C13	55.42 (19)	O5—C18—C19—C20	179.43 (14)
C12—O3—C11—C10	−17.30 (19)	C17—C18—C19—C20	−2.2 (2)
C13—C10—C11—O3	23.87 (17)	O6—C19—C20—C15	−179.96 (14)
C9—C10—C11—O3	150.24 (14)	C18—C19—C20—C15	−0.1 (2)
C11—O3—C12—O4	−177.32 (17)	C16—C15—C20—C19	2.2 (2)
C11—O3—C12—C13	2.8 (2)	C14—C15—C20—C19	−176.31 (14)
O4—C12—C13—C14	−42.2 (2)

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5···O2i	0.90 (2)	2.04 (2)	2.8280 (17)	146 (2)
O5—H5···O6	0.90 (2)	2.22 (2)	2.6799 (18)	111.7 (17)
O5—H5···O1i	0.90 (2)	2.58 (2)	3.2406 (18)	130.8 (16)
C3—H3···O5ii	0.95	2.34	3.278 (2)	168
C14—H14A···O4iii	0.99	2.86	3.687 (2)	142
C14—H14B···O5iv	0.99	2.42	3.373 (2)	162
C20—H20···O4iii	0.95	2.53	3.446 (2)	162

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O5—H5⋯O2i	0.90 (2)	2.04 (2)	2.8280 (17)	146 (2)
O5—H5⋯O6	0.90 (2)	2.22 (2)	2.6799 (18)	111.7 (17)
O5—H5⋯O1i	0.90 (2)	2.58 (2)	3.2406 (18)	130.8 (16)
C3—H3⋯O5ii	0.95	2.34	3.278 (2)	168
C14—H14A⋯O4iii	0.99	2.86	3.687 (2)	142
C14—H14B⋯O5iv	0.99	2.42	3.373 (2)	162
C20—H20⋯O4iii	0.95	2.53	3.446 (2)	162

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .