Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803008948/ya6159sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536803008948/ya6159Isup2.hkl |
CCDC reference: 214809
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.004 Å
- R factor = 0.033
- wR factor = 0.112
- Data-to-parameter ratio = 9.6
checkCIF results
No syntax errors found ADDSYM reports no extra symmetry
Alert Level C:
ABSMU_01 Alert C The ratio of given/expected absorption coefficient lies outside the range 0.99 <> 1.01 Calculated value of mu = 0.106 Value of mu given = 0.110 General Notes
REFLT_03 From the CIF: _diffrn_reflns_theta_max 27.50 From the CIF: _reflns_number_total 2610 Count of symmetry unique reflns 2621 Completeness (_total/calc) 99.58% TEST3: Check Friedels for noncentro structure Estimate of Friedel pairs measured 0 Fraction of Friedel pairs measured 0.000 Are heavy atom types Z>Si present no Please check that the estimate of the number of Friedel pairs is correct. If it is not, please give the correct count in the _publ_section_exptl_refinement section of the submitted CIF.
0 Alert Level A = Potentially serious problem
0 Alert Level B = Potential problem
1 Alert Level C = Please check
Pyridinium dichromate (PDC; 0.89 g, 2.40 mmol) was added to a solution of podophyllotoxin (0.69 g, 1.65 mmol) in dry dichloromethane (20 ml) and stirred at room temperature for 4 h. The excess of PDC was removed by filtration followed by column chromatography of the residue on silica gel to give 520 mg (78%) of podophyllotoxone (Gordaliza et al., 2001). Colorless crystals were obtained from an ethyl acetate solution after it was left to stand for 4 d. C and H were analysed using a Carlo-Erba 1160 instrument. Analysis calculated for C22H20O8: C 64.07, H 4.89%; found: C 63.83, H 4.92%. 1H NMR (CDCl3, 500 MHz): δ 7.55 (s, 1H), 6.71 (s, 1H), 6.39 (s, 2H), 6.10 (ss, 2H), 4.85 (d, 1H), 4.55 and 4.36 (dd, 2H), 3.82 (s, 3H), 3.75 (s, 6H), 3.51 (m, 1H), 3.27 (dd, 1H).
The refinement of the Flack parameter (Flack & Schwarzenbach, 1988) was suppressed by the MERG 4 command in SHELXL97 (Sheldrick, 1997), as the lack of anomalous scatterers did not allow for the absolute configuration to be determined from the X-ray measurements. The absolute configuration was, therefore, chosen on the basis of the known configuration of synthetic precursor. The H atoms of the methyl, methylene, methine groups and of the aromatic ring were placed in calculated positions, with C—H distances of 0.96, 0.97, 0.98 and 0.93 Å, respectively, and were included in the final cycles of least-squares refinement as riding on the carrier atoms, with Uiso(H) = 1.2Ueq of the corresponding carrier atoms (1.5Ueq in case of methyl H atoms).
Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure corporation, 1992); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation, 1993); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and CAMERON (Watkin, 1993); software used to prepare material for publication: WinGX (Farrugia, 1999).
C22H20O8 | F(000) = 864 |
Mr = 412.38 | Dx = 1.386 Mg m−3 Dm = 1.379 Mg m−3 Dm measured by flotation in a mixture of hexane and carbontetrachloride |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 25 reflections |
a = 6.4927 (9) Å | θ = 3.0–26.5° |
b = 12.1940 (11) Å | µ = 0.11 mm−1 |
c = 24.9681 (18) Å | T = 293 K |
V = 1976.8 (4) Å3 | Prism, colorless |
Z = 4 | 0.45 × 0.3 × 0.25 mm |
Rigaku R-AXIS RAPID diffractometer | 1817 reflections with I > 2σ(I) |
ω/2θ scans | Rint = 0.015 |
Absorption correction: ψ scan (North et al., 1968) | θmax = 27.5°, θmin = 1.6° |
Tmin = 0.963, Tmax = 0.974 | h = −8→8 |
4509 measured reflections | k = −15→15 |
2610 independent reflections | l = −32→32 |
Refinement on F2 | H-atom parameters constrained |
Least-squares matrix: full | w = 1/[σ2(Fo2) + (0.0667P)2] where P = (Fo2 + 2Fc2)/3 |
R[F2 > 2σ(F2)] = 0.033 | (Δ/σ)max < 0.001 |
wR(F2) = 0.112 | Δρmax = 0.23 e Å−3 |
S = 0.98 | Δρmin = −0.25 e Å−3 |
2610 reflections | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
272 parameters | Extinction coefficient: 0.0133 (17) |
0 restraints |
C22H20O8 | V = 1976.8 (4) Å3 |
Mr = 412.38 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 6.4927 (9) Å | µ = 0.11 mm−1 |
b = 12.1940 (11) Å | T = 293 K |
c = 24.9681 (18) Å | 0.45 × 0.3 × 0.25 mm |
Rigaku R-AXIS RAPID diffractometer | 2610 independent reflections |
Absorption correction: ψ scan (North et al., 1968) | 1817 reflections with I > 2σ(I) |
Tmin = 0.963, Tmax = 0.974 | Rint = 0.015 |
4509 measured reflections |
R[F2 > 2σ(F2)] = 0.033 | 0 restraints |
wR(F2) = 0.112 | H-atom parameters constrained |
S = 0.98 | Δρmax = 0.23 e Å−3 |
2610 reflections | Δρmin = −0.25 e Å−3 |
272 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
C2 | 0.3339 (7) | −0.2267 (3) | 0.06118 (18) | 0.0853 (12) | |
H2A | 0.2786 | −0.276 | 0.0343 | 0.102* | |
H2B | 0.3792 | −0.2699 | 0.0916 | 0.102* | |
C3A | 0.4716 (6) | −0.0592 (2) | 0.05652 (11) | 0.0527 (8) | |
C4 | 0.5954 (5) | 0.0284 (2) | 0.05157 (11) | 0.0506 (7) | |
H4 | 0.7248 | 0.0222 | 0.0359 | 0.061* | |
C4A | 0.5225 (5) | 0.1307 (2) | 0.07098 (10) | 0.0426 (6) | |
C5 | 0.6568 (5) | 0.2269 (2) | 0.06469 (10) | 0.0451 (6) | |
C5A | 0.5788 (4) | 0.3315 (2) | 0.08826 (11) | 0.0458 (7) | |
H5A | 0.6144 | 0.3326 | 0.1264 | 0.055* | |
C6 | 0.6426 (6) | 0.4404 (3) | 0.06363 (14) | 0.0668 (9) | |
H6A | 0.7728 | 0.4653 | 0.0783 | 0.08* | |
H6B | 0.6551 | 0.4344 | 0.025 | 0.08* | |
C8 | 0.3044 (6) | 0.4577 (3) | 0.09154 (12) | 0.0552 (8) | |
C8A | 0.3467 (5) | 0.3369 (2) | 0.08316 (10) | 0.0447 (7) | |
H8A | 0.3161 | 0.3221 | 0.0454 | 0.054* | |
C9 | 0.2392 (4) | 0.2475 (2) | 0.11477 (10) | 0.0419 (6) | |
H9 | 0.0927 | 0.25 | 0.1054 | 0.05* | |
C9A | 0.3252 (5) | 0.1386 (2) | 0.09408 (10) | 0.0422 (6) | |
C10 | 0.2017 (5) | 0.0453 (3) | 0.09833 (11) | 0.0518 (7) | |
H10 | 0.0713 | 0.0489 | 0.1136 | 0.062* | |
C10A | 0.2784 (5) | −0.0513 (3) | 0.07935 (12) | 0.0548 (8) | |
C11 | 0.2552 (4) | 0.2596 (2) | 0.17518 (10) | 0.0398 (6) | |
C12 | 0.1103 (4) | 0.3232 (2) | 0.20177 (10) | 0.0435 (6) | |
H12 | 0.0054 | 0.3569 | 0.1825 | 0.052* | |
C13 | 0.1204 (5) | 0.3368 (2) | 0.25649 (11) | 0.0470 (7) | |
C13A | −0.1912 (6) | 0.4404 (3) | 0.25986 (15) | 0.0718 (10) | |
H13A | −0.2721 | 0.4813 | 0.2851 | 0.108* | |
H13B | −0.2719 | 0.381 | 0.2458 | 0.108* | |
H13C | −0.1493 | 0.4876 | 0.2311 | 0.108* | |
C14 | 0.2758 (4) | 0.2861 (2) | 0.28575 (10) | 0.0463 (7) | |
C14A | 0.1794 (6) | 0.2143 (3) | 0.36825 (13) | 0.0753 (10) | |
H14A | 0.1906 | 0.2261 | 0.4062 | 0.113* | |
H14B | 0.2388 | 0.1447 | 0.3592 | 0.113* | |
H14C | 0.0368 | 0.215 | 0.358 | 0.113* | |
C15 | 0.4209 (4) | 0.2224 (2) | 0.25943 (10) | 0.0453 (7) | |
C15A | 0.7144 (6) | 0.1063 (3) | 0.26739 (14) | 0.0691 (10) | |
H15A | 0.8075 | 0.0798 | 0.2943 | 0.104* | |
H15B | 0.7899 | 0.147 | 0.241 | 0.104* | |
H15C | 0.6466 | 0.0454 | 0.2506 | 0.104* | |
C16 | 0.4108 (4) | 0.2090 (2) | 0.20434 (10) | 0.0427 (6) | |
H16 | 0.5084 | 0.1661 | 0.1869 | 0.051* | |
O1 | 0.1811 (5) | −0.15024 (19) | 0.07740 (11) | 0.0808 (8) | |
O3 | 0.5046 (5) | −0.16511 (18) | 0.03935 (9) | 0.0726 (7) | |
O5 | 0.8250 (3) | 0.22234 (18) | 0.04240 (8) | 0.0567 (5) | |
O7 | 0.4771 (5) | 0.51390 (17) | 0.07818 (10) | 0.0722 (7) | |
O8 | 0.1495 (4) | 0.50262 (19) | 0.10486 (9) | 0.0713 (7) | |
O13 | −0.0150 (4) | 0.39790 (19) | 0.28581 (8) | 0.0664 (6) | |
O14 | 0.2866 (4) | 0.29970 (18) | 0.34039 (7) | 0.0615 (6) | |
O15 | 0.5659 (4) | 0.1752 (2) | 0.29143 (8) | 0.0647 (6) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C2 | 0.105 (3) | 0.0383 (18) | 0.113 (3) | −0.008 (2) | −0.010 (3) | −0.015 (2) |
C3A | 0.076 (2) | 0.0333 (15) | 0.0491 (15) | 0.0050 (17) | −0.0024 (15) | −0.0062 (12) |
C4 | 0.0602 (19) | 0.0469 (17) | 0.0446 (14) | 0.0085 (16) | 0.0030 (14) | −0.0045 (13) |
C4A | 0.0513 (16) | 0.0384 (15) | 0.0380 (12) | 0.0023 (13) | −0.0010 (12) | −0.0027 (11) |
C5 | 0.0517 (16) | 0.0466 (16) | 0.0371 (13) | −0.0010 (15) | −0.0023 (12) | −0.0027 (12) |
C5A | 0.0575 (17) | 0.0391 (15) | 0.0408 (13) | −0.0051 (14) | 0.0006 (12) | −0.0034 (12) |
C6 | 0.082 (2) | 0.0472 (19) | 0.071 (2) | −0.0079 (19) | 0.012 (2) | 0.0003 (16) |
C8 | 0.079 (2) | 0.0388 (17) | 0.0477 (16) | 0.0044 (19) | −0.0054 (16) | −0.0037 (13) |
C8A | 0.0617 (18) | 0.0375 (15) | 0.0349 (12) | 0.0029 (14) | −0.0054 (12) | −0.0031 (11) |
C9 | 0.0434 (14) | 0.0375 (15) | 0.0449 (13) | 0.0012 (13) | −0.0032 (11) | −0.0045 (11) |
C9A | 0.0495 (16) | 0.0370 (15) | 0.0400 (13) | 0.0015 (14) | −0.0056 (12) | −0.0023 (11) |
C10 | 0.0555 (17) | 0.0432 (17) | 0.0568 (16) | −0.0026 (15) | 0.0023 (14) | −0.0047 (13) |
C10A | 0.070 (2) | 0.0367 (16) | 0.0575 (17) | −0.0091 (16) | −0.0045 (16) | −0.0023 (13) |
C11 | 0.0431 (13) | 0.0322 (14) | 0.0441 (13) | −0.0034 (12) | 0.0022 (11) | −0.0010 (11) |
C12 | 0.0450 (14) | 0.0373 (15) | 0.0481 (14) | 0.0017 (13) | −0.0007 (12) | −0.0005 (12) |
C13 | 0.0521 (16) | 0.0363 (16) | 0.0526 (15) | −0.0006 (14) | 0.0082 (13) | −0.0076 (12) |
C13A | 0.060 (2) | 0.071 (2) | 0.083 (2) | 0.018 (2) | 0.0100 (19) | −0.0140 (19) |
C14 | 0.0565 (17) | 0.0400 (15) | 0.0423 (13) | −0.0055 (14) | 0.0022 (12) | −0.0032 (12) |
C14A | 0.092 (2) | 0.081 (3) | 0.0531 (17) | 0.009 (3) | 0.0121 (19) | 0.0118 (18) |
C15 | 0.0498 (16) | 0.0404 (16) | 0.0458 (14) | 0.0011 (14) | −0.0017 (12) | 0.0046 (12) |
C15A | 0.065 (2) | 0.072 (2) | 0.069 (2) | 0.023 (2) | −0.0089 (18) | 0.0082 (18) |
C16 | 0.0449 (14) | 0.0386 (15) | 0.0447 (13) | 0.0065 (13) | 0.0039 (11) | 0.0000 (12) |
O1 | 0.0935 (18) | 0.0400 (13) | 0.1090 (19) | −0.0135 (14) | 0.0064 (16) | −0.0126 (13) |
O3 | 0.1007 (19) | 0.0381 (12) | 0.0792 (15) | 0.0078 (14) | 0.0064 (15) | −0.0140 (11) |
O5 | 0.0533 (11) | 0.0637 (14) | 0.0532 (10) | −0.0043 (12) | 0.0059 (10) | −0.0082 (10) |
O7 | 0.0936 (18) | 0.0359 (12) | 0.0870 (16) | −0.0020 (13) | 0.0085 (16) | −0.0005 (11) |
O8 | 0.0914 (18) | 0.0474 (14) | 0.0753 (15) | 0.0230 (15) | −0.0043 (14) | −0.0062 (11) |
O13 | 0.0717 (15) | 0.0680 (15) | 0.0596 (12) | 0.0249 (14) | 0.0089 (12) | −0.0127 (11) |
O14 | 0.0795 (15) | 0.0624 (14) | 0.0427 (10) | −0.0008 (13) | −0.0014 (10) | −0.0089 (10) |
O15 | 0.0703 (14) | 0.0737 (16) | 0.0501 (11) | 0.0218 (13) | −0.0076 (10) | 0.0026 (11) |
C2—O1 | 1.420 (5) | C9A—C10 | 1.396 (4) |
C2—O3 | 1.445 (5) | C10—C10A | 1.364 (4) |
C2—H2A | 0.97 | C10—H10 | 0.93 |
C2—H2B | 0.97 | C10A—O1 | 1.363 (4) |
C3A—C4 | 1.343 (4) | C11—C12 | 1.388 (4) |
C3A—O3 | 1.377 (4) | C11—C16 | 1.390 (4) |
C3A—C10A | 1.381 (5) | C12—C13 | 1.378 (4) |
C4—C4A | 1.420 (4) | C12—H12 | 0.93 |
C4—H4 | 0.93 | C13—O13 | 1.365 (3) |
C4A—C9A | 1.408 (4) | C13—C14 | 1.391 (4) |
C4A—C5 | 1.471 (4) | C13A—O13 | 1.413 (4) |
C5—O5 | 1.227 (4) | C13A—H13A | 0.96 |
C5—C5A | 1.492 (4) | C13A—H13B | 0.96 |
C5A—C8A | 1.514 (4) | C13A—H13C | 0.96 |
C5A—C6 | 1.521 (4) | C14—O14 | 1.376 (3) |
C5A—H5A | 0.98 | C14—C15 | 1.386 (4) |
C6—O7 | 1.446 (4) | C14A—O14 | 1.433 (4) |
C6—H6A | 0.97 | C14A—H14A | 0.96 |
C6—H6B | 0.97 | C14A—H14B | 0.96 |
C8—O8 | 1.193 (4) | C14A—H14C | 0.96 |
C8—O7 | 1.356 (4) | C15—O15 | 1.362 (3) |
C8—C8A | 1.513 (4) | C15—C16 | 1.387 (4) |
C8A—C9 | 1.516 (4) | C15A—O15 | 1.413 (4) |
C8A—H8A | 0.98 | C15A—H15A | 0.96 |
C9—C11 | 1.519 (3) | C15A—H15B | 0.96 |
C9—C9A | 1.530 (4) | C15A—H15C | 0.96 |
C9—H9 | 0.98 | C16—H16 | 0.93 |
O1—C2—O3 | 107.6 (3) | C10A—C10—C9A | 117.9 (3) |
O1—C2—H2A | 110.2 | C10A—C10—H10 | 121 |
O3—C2—H2A | 110.2 | C9A—C10—H10 | 121 |
O1—C2—H2B | 110.2 | O1—C10A—C10 | 127.5 (3) |
O3—C2—H2B | 110.2 | O1—C10A—C3A | 110.1 (3) |
H2A—C2—H2B | 108.5 | C10—C10A—C3A | 122.4 (3) |
C4—C3A—O3 | 128.6 (3) | C12—C11—C16 | 119.4 (2) |
C4—C3A—C10A | 121.7 (3) | C12—C11—C9 | 118.9 (2) |
O3—C3A—C10A | 109.6 (3) | C16—C11—C9 | 121.8 (2) |
C3A—C4—C4A | 117.9 (3) | C13—C12—C11 | 120.6 (3) |
C3A—C4—H4 | 121 | C13—C12—H12 | 119.7 |
C4A—C4—H4 | 121 | C11—C12—H12 | 119.7 |
C9A—C4A—C4 | 120.2 (3) | O13—C13—C12 | 124.5 (3) |
C9A—C4A—C5 | 121.9 (2) | O13—C13—C14 | 115.4 (2) |
C4—C4A—C5 | 117.8 (3) | C12—C13—C14 | 120.1 (3) |
O5—C5—C4A | 122.7 (3) | O13—C13A—H13A | 109.5 |
O5—C5—C5A | 121.3 (3) | O13—C13A—H13B | 109.5 |
C4A—C5—C5A | 116.0 (2) | H13A—C13A—H13B | 109.5 |
C5—C5A—C8A | 110.0 (2) | O13—C13A—H13C | 109.5 |
C5—C5A—C6 | 119.6 (2) | H13A—C13A—H13C | 109.5 |
C8A—C5A—C6 | 101.5 (3) | H13B—C13A—H13C | 109.5 |
C5—C5A—H5A | 108.4 | O14—C14—C15 | 120.2 (2) |
C8A—C5A—H5A | 108.4 | O14—C14—C13 | 120.3 (3) |
C6—C5A—H5A | 108.4 | C15—C14—C13 | 119.6 (2) |
O7—C6—C5A | 103.7 (3) | O14—C14A—H14A | 109.5 |
O7—C6—H6A | 111 | O14—C14A—H14B | 109.5 |
C5A—C6—H6A | 111 | H14A—C14A—H14B | 109.5 |
O7—C6—H6B | 111 | O14—C14A—H14C | 109.5 |
C5A—C6—H6B | 111 | H14A—C14A—H14C | 109.5 |
H6A—C6—H6B | 109 | H14B—C14A—H14C | 109.5 |
O8—C8—O7 | 122.3 (3) | O15—C15—C14 | 115.4 (2) |
O8—C8—C8A | 129.7 (3) | O15—C15—C16 | 124.4 (3) |
O7—C8—C8A | 107.9 (3) | C14—C15—C16 | 120.3 (3) |
C8—C8A—C5A | 102.3 (3) | O15—C15A—H15A | 109.5 |
C8—C8A—C9 | 123.0 (3) | O15—C15A—H15B | 109.5 |
C5A—C8A—C9 | 112.5 (2) | H15A—C15A—H15B | 109.5 |
C8—C8A—H8A | 106 | O15—C15A—H15C | 109.5 |
C5A—C8A—H8A | 106 | H15A—C15A—H15C | 109.5 |
C9—C8A—H8A | 106 | H15B—C15A—H15C | 109.5 |
C8A—C9—C11 | 114.6 (2) | C15—C16—C11 | 120.1 (3) |
C8A—C9—C9A | 106.3 (2) | C15—C16—H16 | 119.9 |
C11—C9—C9A | 113.2 (2) | C11—C16—H16 | 119.9 |
C8A—C9—H9 | 107.5 | C10A—O1—C2 | 105.5 (3) |
C11—C9—H9 | 107.5 | C3A—O3—C2 | 104.5 (3) |
C9A—C9—H9 | 107.5 | C8—O7—C6 | 111.3 (2) |
C10—C9A—C4A | 119.8 (3) | C13—O13—C13A | 118.4 (2) |
C10—C9A—C9 | 118.2 (2) | C14—O14—C14A | 111.6 (2) |
C4A—C9A—C9 | 122.0 (2) | C15—O15—C15A | 118.3 (2) |
O3—C3A—C4—C4A | 177.6 (3) | O3—C3A—C10A—O1 | −0.4 (4) |
C10A—C3A—C4—C4A | 0.4 (4) | C4—C3A—C10A—C10 | −0.2 (5) |
C3A—C4—C4A—C9A | −0.6 (4) | O3—C3A—C10A—C10 | −177.8 (3) |
C3A—C4—C4A—C5 | −179.0 (3) | C8A—C9—C11—C12 | 87.0 (3) |
C9A—C4A—C5—O5 | −176.5 (2) | C9A—C9—C11—C12 | −150.9 (2) |
C4—C4A—C5—O5 | 1.8 (4) | C8A—C9—C11—C16 | −92.8 (3) |
C9A—C4A—C5—C5A | 4.9 (4) | C9A—C9—C11—C16 | 29.3 (3) |
C4—C4A—C5—C5A | −176.8 (2) | C16—C11—C12—C13 | 0.3 (4) |
O5—C5—C5A—C8A | 146.8 (3) | C9—C11—C12—C13 | −179.5 (2) |
C4A—C5—C5A—C8A | −34.5 (3) | C11—C12—C13—O13 | 179.9 (3) |
O5—C5—C5A—C6 | 30.1 (4) | C11—C12—C13—C14 | −0.5 (4) |
C4A—C5—C5A—C6 | −151.2 (3) | O13—C13—C14—O14 | −0.5 (4) |
C5—C5A—C6—O7 | 154.7 (3) | C12—C13—C14—O14 | 179.8 (3) |
C8A—C5A—C6—O7 | 33.6 (3) | O13—C13—C14—C15 | −179.9 (3) |
O8—C8—C8A—C5A | −158.8 (3) | C12—C13—C14—C15 | 0.4 (4) |
O7—C8—C8A—C5A | 24.6 (3) | O14—C14—C15—O15 | 1.1 (4) |
O8—C8—C8A—C9 | −31.3 (5) | C13—C14—C15—O15 | −179.5 (3) |
O7—C8—C8A—C9 | 152.0 (3) | O14—C14—C15—C16 | −179.7 (3) |
C5—C5A—C8A—C8 | −162.4 (2) | C13—C14—C15—C16 | −0.2 (4) |
C6—C5A—C8A—C8 | −34.8 (3) | O15—C15—C16—C11 | 179.2 (2) |
C5—C5A—C8A—C9 | 63.8 (3) | C14—C15—C16—C11 | 0.1 (4) |
C6—C5A—C8A—C9 | −168.6 (2) | C12—C11—C16—C15 | −0.1 (4) |
C8—C8A—C9—C11 | −54.3 (4) | C9—C11—C16—C15 | 179.7 (3) |
C5A—C8A—C9—C11 | 68.6 (3) | C10—C10A—O1—C2 | −172.4 (3) |
C8—C8A—C9—C9A | 179.9 (3) | C3A—C10A—O1—C2 | 10.3 (4) |
C5A—C8A—C9—C9A | −57.2 (3) | O3—C2—O1—C10A | −16.1 (4) |
C4—C4A—C9A—C10 | 0.6 (4) | C4—C3A—O3—C2 | 173.0 (3) |
C5—C4A—C9A—C10 | 178.8 (2) | C10A—C3A—O3—C2 | −9.5 (4) |
C4—C4A—C9A—C9 | −179.1 (2) | O1—C2—O3—C3A | 15.7 (4) |
C5—C4A—C9A—C9 | −0.8 (4) | O8—C8—O7—C6 | 180.0 (3) |
C8A—C9—C9A—C10 | −153.6 (3) | C8A—C8—O7—C6 | −3.1 (3) |
C11—C9—C9A—C10 | 79.8 (3) | C5A—C6—O7—C8 | −19.7 (3) |
C8A—C9—C9A—C4A | 26.1 (3) | C12—C13—O13—C13A | 7.5 (5) |
C11—C9—C9A—C4A | −100.5 (3) | C14—C13—O13—C13A | −172.1 (3) |
C4A—C9A—C10—C10A | −0.3 (4) | C15—C14—O14—C14A | −87.7 (3) |
C9—C9A—C10—C10A | 179.4 (2) | C13—C14—O14—C14A | 92.9 (3) |
C9A—C10—C10A—O1 | −176.9 (3) | C14—C15—O15—C15A | 178.0 (3) |
C9A—C10—C10A—C3A | 0.1 (4) | C16—C15—O15—C15A | −1.2 (4) |
C4—C3A—C10A—O1 | 177.3 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
C6—H6A···O8i | 0.97 | 2.57 | 3.531 (5) | 169 |
C9—H9···O5ii | 0.98 | 2.37 | 3.254 (3) | 150 |
C8A—H8A···O5iii | 0.98 | 2.26 | 3.220 (3) | 167 |
Symmetry codes: (i) x+1, y, z; (ii) x−1, y, z; (iii) x−1/2, −y+1/2, −z. |
Experimental details
Crystal data | |
Chemical formula | C22H20O8 |
Mr | 412.38 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 293 |
a, b, c (Å) | 6.4927 (9), 12.1940 (11), 24.9681 (18) |
V (Å3) | 1976.8 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.45 × 0.3 × 0.25 |
Data collection | |
Diffractometer | Rigaku R-AXIS RAPID diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.963, 0.974 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4509, 2610, 1817 |
Rint | 0.015 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.033, 0.112, 0.98 |
No. of reflections | 2610 |
No. of parameters | 272 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.23, −0.25 |
Computer programs: MSC/AFC Diffractometer Control Software (Molecular Structure corporation, 1992), MSC/AFC Diffractometer Control Software, TEXSAN (Molecular Structure Corporation, 1993), SIR92 (Altomare et al., 1993), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997) and CAMERON (Watkin, 1993), WinGX (Farrugia, 1999).
D—H···A | D—H | H···A | D···A | D—H···A |
C6—H6A···O8i | 0.97 | 2.57 | 3.531 (5) | 169 |
C9—H9···O5ii | 0.98 | 2.37 | 3.254 (3) | 150 |
C8A—H8A···O5iii | 0.98 | 2.26 | 3.220 (3) | 167 |
Symmetry codes: (i) x+1, y, z; (ii) x−1, y, z; (iii) x−1/2, −y+1/2, −z. |
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Podophyllotoxin is a lignan of phenyltetralin type, which is widespread in higher plants. The discovery of the antitumour activity of etoposide (VP-16) and teniposide (VM-26), semisynthetic analogues of the naturally occurring podophyllotoxin, has stirred up the renewed interest in this field in the recent years (Damayanthi & Lown, 1998; Silverberg et al., 2000; Van Vliet et al., 2001). In a continuation of our previous work (Xu et al., 2002; Ma et al., 2000; Cao et al., 1999), we have synthesized potential antitumour agents with the structure of 4-heterocyclespiropodophyllotoxins using the title compound, podophyllotoxone, (I), as a starting material. Herein we report the crystal structure of (I).
The molecular structure of (I) is shown in Fig. 1. Selected molecular parameters and hydrogen-bond geometric characteristics are listed in Tables 1 and 2, respectively. The relative configuration of the chiral centres at atoms C5a, C8a and C9 is the same as in the starting compound, podophyllotoxin, which was not unexpected, as the chiral centres were not affected by the reaction. The absolute configuration was chosen in accordance with the known configuration of podophyllotoxin (Gordaliza et al., 2001). Atom H8a in (I) is cis relative to H9 and trans relative to H5a. The observed trans-fusion of the γ-lactone was proved essential to the bioactivity of podophyllotoxin derivatives (Brewer et al., 1979). The loss of activity of picropodophyllotoxin, which contains a cis-fused γ-lactone, has been attributed to differences in the conformation (Gensler et al., 1977).
In the crystal structure, non-classical C—H···O hydrogen bonds play an important role, resulting in the formation of polymeric chains of the molecules of the title compounds running along the crystallographic a axis.