1,3-Bis(3,4,5-trimethoxy­phen­yl)-2,3-epoxy­propanone: an anti­cancer chalcone epoxide

The title compound, C₂₁H₂₄O₈, crystallizes as colorless needles composed of a racemic mixture that adopts the packing order of columns of alternating enanti­omers, all of whose oxirane rings are essentially aligned. Within each column, the carbonyl groups of adjacent enanti­omers are oriented in nearly opposite directions. The structure is stabilized by several C—H...O associations.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.063
• wR factor = 0.137
• Data-to-parameter ratio = 13.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.23
PLAT432_ALERT_2_C Short Inter X...Y Contact  O12    ..  C1J     ..       3.00 Ang.
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........         22

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 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
   2 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: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL.

1,3-Bis(3,4,5-trimethoxyphenyl)-2,3-epoxypropanone

Crystal data

C21H24O8	F(000) = 1712
Mr = 404.40	Dx = 1.359 Mg m^−3
Orthorhombic, Pbcn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2ab	Cell parameters from 6496 reflections
a = 18.5563 (11) Å	θ = 2.2–27.5°
b = 7.7666 (5) Å	µ = 0.10 mm^−1
c = 27.4354 (17) Å	T = 173 K
V = 3954.0 (4) Å^3	Needle, colorless
Z = 8	0.37 × 0.12 × 0.08 mm

Data collection

Bruker SMART APEX diffractometer	3038 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.052
Graphite monochromator	θmax = 25.0°, θmin = 1.9°
ω scans	h = −22→22
29894 measured reflections	k = −9→9
3490 independent reflections	l = −32→32

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)] = 0.063	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.137	H atoms treated by a mixture of independent and constrained refinement
S = 1.19	w = 1/[σ^2(Fo^2) + (0.0446P)^2 + 3.305P] where P = (Fo^2 + 2Fc^2)/3
3490 reflections	(Δ/σ)max < 0.001
268 parameters	Δρmax = 0.47 e Å^−3
0 restraints	Δρmin = −0.21 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
C1A	0.34402 (14)	0.9718 (3)	0.52412 (8)	0.0315 (6)
C1B	0.33773 (14)	0.8242 (3)	0.55234 (9)	0.0337 (6)
H1BA	0.2968	0.7518	0.5491	0.040*
C1C	0.39164 (15)	0.7835 (3)	0.58525 (9)	0.0354 (6)
C1D	0.45213 (14)	0.8889 (3)	0.58990 (9)	0.0334 (6)
C1E	0.45777 (14)	1.0375 (3)	0.56174 (9)	0.0334 (6)
C1F	0.40335 (14)	1.0793 (3)	0.52889 (9)	0.0337 (6)
H1FA	0.4068	1.1810	0.5098	0.040*
C1G	0.32922 (18)	0.5347 (4)	0.61404 (12)	0.0575 (9)
H1GA	0.3329	0.4476	0.6397	0.086*
H1GB	0.3261	0.4778	0.5822	0.086*
H1GC	0.2859	0.6045	0.6193	0.086*
C1H	0.55028 (17)	0.7134 (4)	0.61332 (11)	0.0486 (8)
H1HA	0.5939	0.7201	0.6334	0.073*
H1HB	0.5637	0.7159	0.5788	0.073*
H1HC	0.5247	0.6059	0.6205	0.073*
C1I	0.52601 (16)	1.2888 (4)	0.54232 (10)	0.0457 (7)
H1IA	0.5713	1.3452	0.5514	0.069*
H1IB	0.4855	1.3653	0.5499	0.069*
H1IC	0.5263	1.2633	0.5073	0.069*
C1J	0.28645 (15)	1.0125 (3)	0.48787 (9)	0.0326 (6)
H1J	0.2347 (14)	0.969 (3)	0.4929 (9)	0.033*
O1C	0.39112 (11)	0.6425 (3)	0.61520 (7)	0.0450 (5)
O1D	0.50456 (11)	0.8565 (3)	0.62402 (7)	0.0449 (5)
O1E	0.51858 (10)	1.1329 (3)	0.56902 (7)	0.0420 (5)
C2A	0.26575 (13)	0.9349 (3)	0.34943 (9)	0.0304 (6)
C2B	0.21257 (14)	0.9226 (3)	0.31388 (9)	0.0321 (6)
H2BA	0.1640	0.9500	0.3217	0.038*
C2C	0.23029 (14)	0.8705 (3)	0.26718 (9)	0.0322 (6)
C2D	0.30195 (14)	0.8334 (3)	0.25559 (9)	0.0327 (6)
C2E	0.35429 (14)	0.8387 (3)	0.29186 (10)	0.0342 (6)
C2F	0.33653 (14)	0.8904 (3)	0.33872 (9)	0.0333 (6)
H2FA	0.3725	0.8954	0.3633	0.040*
C2G	0.10813 (16)	0.8627 (4)	0.24106 (11)	0.0495 (8)
H2GA	0.0797	0.8379	0.2118	0.074*
H2GB	0.0969	0.9791	0.2526	0.074*
H2GC	0.0963	0.7789	0.2665	0.074*
C2H	0.34284 (16)	0.9307 (4)	0.18039 (10)	0.0427 (7)
H2HA	0.3516	0.8934	0.1468	0.064*
H2HB	0.3874	0.9783	0.1941	0.064*
H2HC	0.3052	1.0191	0.1807	0.064*
C2I	0.47350 (16)	0.7619 (4)	0.31567 (11)	0.0490 (8)
H2IA	0.5177	0.7139	0.3017	0.074*
H2IB	0.4539	0.6815	0.3398	0.074*
H2IC	0.4844	0.8720	0.3315	0.074*
C2J	0.24450 (14)	0.9997 (3)	0.39850 (9)	0.0318 (6)
O2C	0.18288 (10)	0.8517 (3)	0.22970 (6)	0.0413 (5)
O2D	0.32015 (11)	0.7866 (2)	0.20895 (6)	0.0400 (5)
O2E	0.42168 (10)	0.7888 (3)	0.27776 (7)	0.0464 (5)
O2J	0.18284 (10)	1.0338 (3)	0.40856 (6)	0.0419 (5)
C12	0.30286 (16)	1.0325 (4)	0.43588 (10)	0.0389 (7)
H12	0.3521 (16)	1.016 (4)	0.4264 (10)	0.047*
O12	0.28874 (11)	1.1788 (2)	0.46684 (7)	0.0470 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1A	0.0365 (14)	0.0333 (14)	0.0246 (13)	0.0008 (11)	0.0016 (11)	−0.0085 (11)
C1B	0.0390 (15)	0.0347 (15)	0.0274 (13)	−0.0031 (12)	0.0005 (11)	−0.0044 (11)
C1C	0.0477 (17)	0.0345 (15)	0.0239 (13)	0.0025 (13)	0.0005 (11)	−0.0022 (11)
C1D	0.0422 (15)	0.0348 (15)	0.0232 (12)	0.0039 (12)	−0.0041 (11)	−0.0056 (11)
C1E	0.0379 (15)	0.0360 (15)	0.0263 (13)	−0.0004 (12)	−0.0005 (11)	−0.0096 (11)
C1F	0.0448 (16)	0.0303 (14)	0.0259 (13)	0.0019 (12)	0.0011 (11)	−0.0030 (11)
C1G	0.067 (2)	0.054 (2)	0.0523 (19)	−0.0164 (17)	−0.0071 (16)	0.0158 (16)
C1H	0.0480 (18)	0.0475 (18)	0.0502 (18)	0.0065 (14)	−0.0108 (14)	0.0050 (15)
C1I	0.0521 (18)	0.0440 (17)	0.0411 (16)	−0.0152 (14)	0.0006 (14)	−0.0074 (14)
C1J	0.0434 (16)	0.0263 (14)	0.0282 (13)	0.0042 (12)	−0.0012 (12)	−0.0032 (11)
O1C	0.0563 (13)	0.0428 (12)	0.0359 (10)	−0.0059 (10)	−0.0079 (9)	0.0088 (9)
O1D	0.0539 (12)	0.0441 (12)	0.0365 (10)	0.0050 (10)	−0.0162 (9)	−0.0059 (9)
O1E	0.0449 (12)	0.0440 (12)	0.0371 (10)	−0.0093 (9)	−0.0070 (9)	−0.0024 (9)
C2A	0.0375 (14)	0.0251 (13)	0.0286 (13)	−0.0003 (11)	−0.0001 (11)	0.0056 (11)
C2B	0.0338 (14)	0.0317 (14)	0.0307 (13)	0.0025 (11)	0.0022 (11)	0.0060 (11)
C2C	0.0440 (16)	0.0251 (13)	0.0275 (13)	0.0004 (11)	−0.0011 (11)	0.0033 (10)
C2D	0.0449 (16)	0.0256 (13)	0.0276 (13)	−0.0009 (12)	0.0056 (12)	−0.0009 (11)
C2E	0.0373 (15)	0.0277 (14)	0.0374 (14)	0.0025 (12)	0.0050 (12)	−0.0034 (12)
C2F	0.0371 (15)	0.0313 (14)	0.0315 (14)	−0.0016 (11)	−0.0034 (11)	−0.0019 (11)
C2G	0.0453 (18)	0.061 (2)	0.0427 (17)	0.0077 (15)	−0.0090 (14)	−0.0072 (15)
C2H	0.0487 (17)	0.0485 (18)	0.0310 (14)	−0.0038 (14)	0.0049 (13)	0.0004 (13)
C2I	0.0374 (16)	0.060 (2)	0.0498 (17)	0.0054 (14)	−0.0010 (14)	−0.0140 (16)
C2J	0.0353 (15)	0.0286 (13)	0.0315 (13)	0.0025 (11)	0.0020 (12)	0.0055 (11)
O2C	0.0458 (11)	0.0498 (12)	0.0281 (10)	0.0026 (9)	−0.0063 (8)	−0.0009 (9)
O2D	0.0535 (12)	0.0355 (11)	0.0310 (10)	−0.0018 (9)	0.0080 (9)	−0.0052 (8)
O2E	0.0382 (11)	0.0604 (14)	0.0407 (11)	0.0065 (10)	0.0012 (9)	−0.0156 (10)
O2J	0.0360 (11)	0.0586 (13)	0.0311 (10)	0.0056 (9)	0.0018 (8)	−0.0014 (9)
C12	0.0403 (16)	0.0427 (17)	0.0338 (15)	0.0041 (13)	0.0046 (12)	0.0014 (12)
O12	0.0609 (13)	0.0322 (11)	0.0477 (12)	0.0016 (9)	−0.0073 (10)	−0.0020 (9)

Geometric parameters (Å, º)

C1A—C1F	1.388 (4)	C2A—C2B	1.391 (3)
C1A—C1B	1.388 (4)	C2A—C2J	1.490 (3)
C1A—C1J	1.493 (4)	C2B—C2C	1.384 (3)
C1B—C1C	1.384 (4)	C2B—H2BA	0.9500
C1B—H1BA	0.9500	C2C—O2C	1.361 (3)
C1C—O1C	1.369 (3)	C2C—C2D	1.397 (4)
C1C—C1D	1.395 (4)	C2D—O2D	1.372 (3)
C1D—O1D	1.374 (3)	C2D—C2E	1.391 (4)
C1D—C1E	1.393 (4)	C2E—O2E	1.365 (3)
C1E—O1E	1.365 (3)	C2E—C2F	1.387 (4)
C1E—C1F	1.392 (4)	C2F—H2FA	0.9500
C1F—H1FA	0.9500	C2G—O2C	1.424 (3)
C1G—O1C	1.422 (4)	C2G—H2GA	0.9800
C1G—H1GA	0.9800	C2G—H2GB	0.9800
C1G—H1GB	0.9800	C2G—H2GC	0.9800
C1G—H1GC	0.9800	C2H—O2D	1.430 (3)
C1H—O1D	1.429 (4)	C2H—H2HA	0.9800
C1H—H1HA	0.9800	C2H—H2HB	0.9800
C1H—H1HB	0.9800	C2H—H2HC	0.9800
C1H—H1HC	0.9800	C2I—O2E	1.432 (3)
C1I—O1E	1.422 (3)	C2I—H2IA	0.9800
C1I—H1IA	0.9800	C2I—H2IB	0.9800
C1I—H1IB	0.9800	C2I—H2IC	0.9800
C1I—H1IC	0.9800	C2J—O2J	1.206 (3)
C1J—O12	1.415 (3)	C2J—C12	1.513 (4)
C1J—C12	1.467 (4)	C12—O12	1.443 (3)
C1J—H1J	1.03 (3)	C12—H12	0.96 (3)
C2A—C2F	1.390 (4)
C1F—C1A—C1B	120.7 (2)	C2B—C2A—C2J	118.0 (2)
C1F—C1A—C1J	120.2 (2)	C2C—C2B—C2A	120.1 (2)
C1B—C1A—C1J	119.1 (2)	C2C—C2B—H2BA	120.0
C1C—C1B—C1A	119.5 (2)	C2A—C2B—H2BA	120.0
C1C—C1B—H1BA	120.3	O2C—C2C—C2B	125.3 (2)
C1A—C1B—H1BA	120.3	O2C—C2C—C2D	114.9 (2)
O1C—C1C—C1B	124.7 (3)	C2B—C2C—C2D	119.8 (2)
O1C—C1C—C1D	114.8 (2)	O2D—C2D—C2E	120.2 (2)
C1B—C1C—C1D	120.5 (2)	O2D—C2D—C2C	120.1 (2)
O1D—C1D—C1E	118.5 (2)	C2E—C2D—C2C	119.7 (2)
O1D—C1D—C1C	121.7 (2)	O2E—C2E—C2F	124.2 (2)
C1E—C1D—C1C	119.7 (2)	O2E—C2E—C2D	115.4 (2)
O1E—C1E—C1F	124.6 (2)	C2F—C2E—C2D	120.4 (2)
O1E—C1E—C1D	115.5 (2)	C2E—C2F—C2A	119.5 (2)
C1F—C1E—C1D	119.9 (2)	C2E—C2F—H2FA	120.2
C1A—C1F—C1E	119.8 (2)	C2A—C2F—H2FA	120.2
C1A—C1F—H1FA	120.1	O2C—C2G—H2GA	109.5
C1E—C1F—H1FA	120.1	O2C—C2G—H2GB	109.5
O1C—C1G—H1GA	109.5	H2GA—C2G—H2GB	109.5
O1C—C1G—H1GB	109.5	O2C—C2G—H2GC	109.5
H1GA—C1G—H1GB	109.5	H2GA—C2G—H2GC	109.5
O1C—C1G—H1GC	109.5	H2GB—C2G—H2GC	109.5
H1GA—C1G—H1GC	109.5	O2D—C2H—H2HA	109.5
H1GB—C1G—H1GC	109.5	O2D—C2H—H2HB	109.5
O1D—C1H—H1HA	109.5	H2HA—C2H—H2HB	109.5
O1D—C1H—H1HB	109.5	O2D—C2H—H2HC	109.5
H1HA—C1H—H1HB	109.5	H2HA—C2H—H2HC	109.5
O1D—C1H—H1HC	109.5	H2HB—C2H—H2HC	109.5
H1HA—C1H—H1HC	109.5	O2E—C2I—H2IA	109.5
H1HB—C1H—H1HC	109.5	O2E—C2I—H2IB	109.5
O1E—C1I—H1IA	109.5	H2IA—C2I—H2IB	109.5
O1E—C1I—H1IB	109.5	O2E—C2I—H2IC	109.5
H1IA—C1I—H1IB	109.5	H2IA—C2I—H2IC	109.5
O1E—C1I—H1IC	109.5	H2IB—C2I—H2IC	109.5
H1IA—C1I—H1IC	109.5	O2J—C2J—C2A	122.1 (2)
H1IB—C1I—H1IC	109.5	O2J—C2J—C12	119.1 (2)
O12—C1J—C12	60.04 (17)	C2A—C2J—C12	118.7 (2)
O12—C1J—C1A	116.3 (2)	C2C—O2C—C2G	117.2 (2)
C12—C1J—C1A	121.4 (2)	C2D—O2D—C2H	112.1 (2)
O12—C1J—H1J	112.4 (14)	C2E—O2E—C2I	116.8 (2)
C12—C1J—H1J	111.1 (14)	O12—C12—C1J	58.21 (16)
C1A—C1J—H1J	120.7 (14)	O12—C12—C2J	113.7 (2)
C1C—O1C—C1G	117.6 (2)	C1J—C12—C2J	119.5 (2)
C1D—O1D—C1H	115.0 (2)	O12—C12—H12	116.1 (18)
C1E—O1E—C1I	117.9 (2)	C1J—C12—H12	116.6 (17)
C2F—C2A—C2B	120.3 (2)	C2J—C12—H12	118.3 (17)
C2F—C2A—C2J	121.7 (2)	C1J—O12—C12	61.76 (17)