Tlatlancuayin

The biologically active title compound, 2',5-di­methoxy-6,7-(methyl­ene­dioxy)­isoflavone, C₁₈H₁₄O₆, was isolated from the aerial parts of Iresine herbstii Hook (Amaranthaceae). The 1,3-dioxolane ring, fused to the benzo­pyran ring system, adopts an envelope conformation. The dihedral angle between the benzo­pyran ring system and the 3-phenyl ring is 62.75 (6)°.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.036
• wR factor = 0.095
• Data-to-parameter ratio = 11.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT432_ALERT_2_C Short Inter X...Y Contact  C1     ..  C16     ..       3.13 Ang.

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2004); cell refinement: CrysAlis RED (Oxford Diffraction, 2004); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: SHELXL97 and PARST (Nardelli, 1995).

2',5-dimethoxy-6,7-methylenedioxyisoflavone

Crystal data

C18H14O6	Dx = 1.516 Mg m^−3
Mr = 326.29	Melting point: 420.65 K
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 11.262 (3) Å	Cell parameters from 2626 reflections
b = 7.6872 (19) Å	θ = 2.6–27.5°
c = 16.540 (4) Å	µ = 0.12 mm^−1
β = 93.26 (2)°	T = 120 K
V = 1429.6 (6) Å^3	Prism, light brown
Z = 4	0.50 × 0.30 × 0.30 mm
F(000) = 680

Data collection

Kuma KM-4 CCD diffractometer	2191 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.044
Enhance (Oxford Diffraction) monochromator	θmax = 25.0°, θmin = 3.1°
Detector resolution: 16.3 pixels mm^-1	h = −13→13
ω scans	k = −9→6
7787 measured reflections	l = −19→19
2513 independent reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.095	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.05P)^2 + 0.6P] where P = (Fo^2 + 2Fc^2)/3
2513 reflections	(Δ/σ)max < 0.001
219 parameters	Δρmax = 0.21 e Å^−3
0 restraints	Δρmin = −0.23 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.66163 (9)	1.00762 (13)	0.36588 (6)	0.0202 (3)
O2	0.65600 (9)	0.78406 (14)	0.14191 (6)	0.0221 (3)
O3	0.89872 (9)	0.69849 (14)	0.17282 (6)	0.0231 (3)
O4	1.08534 (9)	0.72136 (14)	0.29725 (6)	0.0245 (3)
O5	1.06676 (9)	0.84629 (14)	0.42315 (6)	0.0249 (3)
O6	0.55584 (9)	1.16211 (14)	0.09673 (6)	0.0235 (3)
C1	0.56641 (13)	1.02097 (19)	0.31240 (9)	0.0189 (3)
H1	0.4975	1.0776	0.3300	0.023*
C2	0.56271 (13)	0.95978 (18)	0.23628 (8)	0.0175 (3)
C3	0.66317 (13)	0.86185 (18)	0.20743 (8)	0.0174 (3)
C4	0.88082 (13)	0.78402 (18)	0.24385 (9)	0.0180 (3)
C5	0.97300 (13)	0.79029 (19)	0.30156 (9)	0.0193 (3)
C6	0.96182 (13)	0.86514 (19)	0.37721 (9)	0.0197 (3)
C7	0.85872 (13)	0.93934 (19)	0.39945 (9)	0.0198 (3)
H7	0.8514	0.9905	0.4512	0.024*
C8	0.76422 (13)	0.93469 (18)	0.34047 (9)	0.0178 (3)
C9	0.77037 (13)	0.86105 (17)	0.26327 (8)	0.0171 (3)
C10	1.15192 (14)	0.7918 (2)	0.36634 (9)	0.0257 (4)
H10A	1.2003	0.8921	0.3501	0.031*
H10B	1.2059	0.7025	0.3911	0.031*
C11	0.45166 (13)	0.98206 (18)	0.18352 (9)	0.0184 (3)
C12	0.45098 (13)	1.08098 (18)	0.11195 (9)	0.0191 (3)
C13	0.34742 (13)	1.09308 (19)	0.06171 (9)	0.0221 (3)
H13	0.3473	1.1576	0.0127	0.027*
C14	0.24483 (14)	1.0104 (2)	0.08368 (9)	0.0240 (3)
H14	0.1748	1.0173	0.0490	0.029*
C15	0.24270 (13)	0.9181 (2)	0.15539 (10)	0.0240 (3)
H15	0.1713	0.8645	0.1707	0.029*
C16	0.34643 (13)	0.90465 (19)	0.20485 (9)	0.0211 (3)
H16	0.3453	0.8414	0.2541	0.025*
C17	0.55261 (14)	1.2800 (2)	0.02926 (9)	0.0251 (4)
H17A	0.5344	1.2153	−0.0210	0.038*
H17B	0.6301	1.3370	0.0266	0.038*
H17C	0.4911	1.3681	0.0361	0.038*
C18	0.91178 (14)	0.8101 (2)	0.10428 (9)	0.0271 (4)
H18A	0.8343	0.8596	0.0870	0.041*
H18B	0.9425	0.7426	0.0598	0.041*
H18C	0.9674	0.9042	0.1193	0.041*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0201 (5)	0.0234 (5)	0.0170 (5)	0.0025 (4)	0.0004 (4)	−0.0012 (4)
O2	0.0192 (5)	0.0280 (6)	0.0190 (5)	−0.0012 (4)	−0.0012 (4)	−0.0039 (4)
O3	0.0260 (6)	0.0252 (6)	0.0181 (5)	0.0057 (5)	0.0004 (4)	−0.0037 (4)
O4	0.0176 (5)	0.0316 (6)	0.0241 (6)	0.0052 (5)	−0.0018 (4)	−0.0024 (5)
O5	0.0187 (5)	0.0354 (6)	0.0201 (6)	0.0006 (5)	−0.0038 (4)	−0.0002 (5)
O6	0.0208 (5)	0.0260 (6)	0.0234 (6)	−0.0020 (4)	−0.0007 (4)	0.0080 (4)
C1	0.0170 (7)	0.0199 (7)	0.0196 (7)	0.0018 (6)	−0.0002 (6)	0.0033 (6)
C2	0.0175 (7)	0.0155 (7)	0.0194 (7)	−0.0017 (6)	0.0001 (6)	0.0036 (6)
C3	0.0195 (7)	0.0149 (7)	0.0179 (7)	−0.0028 (6)	0.0008 (6)	0.0026 (6)
C4	0.0206 (7)	0.0158 (7)	0.0176 (7)	−0.0005 (6)	0.0004 (6)	0.0012 (6)
C5	0.0174 (7)	0.0182 (7)	0.0224 (8)	0.0014 (6)	0.0027 (6)	0.0025 (6)
C6	0.0180 (7)	0.0205 (7)	0.0200 (7)	−0.0034 (6)	−0.0045 (6)	0.0041 (6)
C7	0.0226 (8)	0.0209 (7)	0.0158 (7)	−0.0024 (6)	−0.0001 (6)	−0.0002 (6)
C8	0.0176 (7)	0.0156 (7)	0.0204 (7)	−0.0002 (6)	0.0021 (6)	0.0025 (6)
C9	0.0192 (7)	0.0143 (7)	0.0178 (7)	−0.0010 (6)	0.0007 (6)	0.0024 (5)
C10	0.0195 (8)	0.0316 (9)	0.0257 (8)	0.0017 (7)	−0.0022 (6)	−0.0009 (7)
C11	0.0183 (7)	0.0166 (7)	0.0202 (7)	0.0034 (6)	−0.0007 (6)	−0.0022 (6)
C12	0.0196 (7)	0.0170 (7)	0.0210 (7)	0.0020 (6)	0.0023 (6)	−0.0020 (6)
C13	0.0249 (8)	0.0211 (8)	0.0201 (7)	0.0038 (6)	−0.0015 (6)	0.0000 (6)
C14	0.0203 (8)	0.0256 (8)	0.0255 (8)	0.0032 (6)	−0.0050 (6)	−0.0027 (6)
C15	0.0179 (7)	0.0233 (8)	0.0308 (8)	0.0002 (6)	0.0015 (6)	0.0004 (6)
C16	0.0227 (8)	0.0190 (7)	0.0216 (8)	0.0026 (6)	0.0026 (6)	0.0021 (6)
C17	0.0276 (8)	0.0255 (8)	0.0223 (8)	0.0011 (7)	0.0025 (6)	0.0077 (6)
C18	0.0244 (8)	0.0383 (9)	0.0188 (8)	0.0016 (7)	0.0021 (6)	−0.0005 (7)

Geometric parameters (Å, º)

O1—C1	1.3547 (18)	C7—H7	0.9500
O1—C8	1.3714 (18)	C8—C9	1.402 (2)
O2—C3	1.2364 (17)	C10—H10A	0.9900
O3—C4	1.3712 (18)	C10—H10B	0.9900
O3—C18	1.4358 (19)	C11—C16	1.389 (2)
O4—C5	1.3772 (18)	C11—C12	1.407 (2)
O4—C10	1.4366 (19)	C12—C13	1.396 (2)
O5—C6	1.3759 (17)	C13—C14	1.385 (2)
O5—C10	1.4425 (19)	C13—H13	0.9500
O6—C12	1.3715 (18)	C14—C15	1.384 (2)
O6—C17	1.4364 (18)	C14—H14	0.9500
C1—C2	1.342 (2)	C15—C16	1.391 (2)
C1—H1	0.9500	C15—H15	0.9500
C2—C3	1.461 (2)	C16—H16	0.9500
C2—C11	1.494 (2)	C17—H17A	0.9800
C3—C9	1.478 (2)	C17—H17B	0.9800
C4—C5	1.371 (2)	C17—H17C	0.9800
C4—C9	1.431 (2)	C18—H18A	0.9800
C5—C6	1.389 (2)	C18—H18B	0.9800
C6—C7	1.363 (2)	C18—H18C	0.9800
C7—C8	1.403 (2)
C1—O1—C8	118.70 (11)	O5—C10—H10A	110.3
C4—O3—C18	114.63 (11)	O4—C10—H10B	110.3
C5—O4—C10	104.67 (11)	O5—C10—H10B	110.3
C6—O5—C10	104.64 (11)	H10A—C10—H10B	108.6
C12—O6—C17	116.46 (11)	C16—C11—C12	118.77 (13)
C2—C1—O1	124.54 (13)	C16—C11—C2	120.03 (13)
C2—C1—H1	117.7	C12—C11—C2	121.20 (13)
O1—C1—H1	117.7	O6—C12—C13	124.01 (13)
C1—C2—C3	120.23 (13)	O6—C12—C11	115.90 (12)
C1—C2—C11	119.22 (13)	C13—C12—C11	120.09 (13)
C3—C2—C11	120.42 (12)	C14—C13—C12	119.63 (14)
O2—C3—C2	121.48 (13)	C14—C13—H13	120.2
O2—C3—C9	123.79 (13)	C12—C13—H13	120.2
C2—C3—C9	114.72 (12)	C15—C14—C13	121.04 (14)
C5—C4—O3	118.10 (13)	C15—C14—H14	119.5
C5—C4—C9	117.58 (13)	C13—C14—H14	119.5
O3—C4—C9	124.26 (13)	C14—C15—C16	119.14 (14)
C4—C5—O4	127.75 (13)	C14—C15—H15	120.4
C4—C5—C6	122.54 (14)	C16—C15—H15	120.4
O4—C5—C6	109.66 (12)	C11—C16—C15	121.25 (14)
C7—C6—O5	127.82 (13)	C11—C16—H16	119.4
C7—C6—C5	122.59 (13)	C15—C16—H16	119.4
O5—C6—C5	109.56 (13)	O6—C17—H17A	109.5
C6—C7—C8	115.21 (13)	O6—C17—H17B	109.5
C6—C7—H7	122.4	H17A—C17—H17B	109.5
C8—C7—H7	122.4	O6—C17—H17C	109.5
O1—C8—C9	122.02 (13)	H17A—C17—H17C	109.5
O1—C8—C7	113.30 (12)	H17B—C17—H17C	109.5
C9—C8—C7	124.67 (13)	O3—C18—H18A	109.5
C8—C9—C4	117.40 (13)	O3—C18—H18B	109.5
C8—C9—C3	119.12 (13)	H18A—C18—H18B	109.5
C4—C9—C3	123.46 (13)	O3—C18—H18C	109.5
O4—C10—O5	106.94 (12)	H18A—C18—H18C	109.5
O4—C10—H10A	110.3	H18B—C18—H18C	109.5
C9—C4—O3—C18	76.51 (17)	C11—C12—O6—C17	−172.77 (12)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C18—H18A···O2	0.98	2.32	2.988 (2)	124
C1—H1···O2^i	0.95	2.41	3.3393 (19)	165
C7—H7···O5^ii	0.95	2.55	3.4276 (19)	153
C13—H13···O2^iii	0.95	2.59	3.496 (2)	158
C15—H15···O4^iv	0.95	2.60	3.377 (2)	139

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