9,10 De­hydro­de­oxy­artemisinin

organic papers

o1898

15H22O4 doi:10.1107/S1600536806013109 Acta Cryst.(2006). E62, o1898–o1900

Acta Crystallographica Section E Structure Reports Online

ISSN 1600-5368

9,10-Dehydrodeoxyartemisinin

Shu-Hui Li, Zheng-Yu Yue,* Po Gao and Peng-Fei Yan

School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, People’s Republic of China

Correspondence e-mail: yuezhengyu@vip.sina.com

Key indicators

Single-crystal X-ray study

T= 295 K

Mean(C–C) = 0.003 A˚

Rfactor = 0.035

wRfactor = 0.101

Data-to-parameter ratio = 10.8

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

Received 29 March 2006 Accepted 10 April 2006

#2006 International Union of Crystallography All rights reserved

The title compound, C15H22O4, obtained from the dehydration

of dihydroartemisinin, has retained the endoperoxide bridge of the parent compound along with the C C bond. The six-membered rings exhibit chair, twist–boat and envelope conformations.

Comment

Dihydroartemisinin, (II), derived from artemisinin, is found to possess antimalarial activity on account of the retention of the endoperoxide bridge of the parent compound (Posner & O’Neill, 2004). The title compound, 9,10-dehydrodeoxy-artemisinin, (I), a dehydrated product of (II), shows the same antimalarial activity as artemisinin (Liet al., 1981). It is also a key intermediate in the synthesis of artemisinin derivatives (Lin et al., 1990; El-Feraly et al., 1990). The X-ray crystal structure of artemisinin (Qinghaosu Research Group, 1980) and artemisinin derivatives have been reported, including dihydroartemisinin, artemether, artesunic acid (Luo et al., 1984), both cis (Brossi et al., 1988) and trans (Dominguez Gerpe et al., 1988) deoxyarteether, a symmetric form of the ether dimer of deoxydihydroartemisinin (Flippen-Andersonet al., 1989), and-artesunate and-artesunate (Haynes et al., 2002). We report here the crystal structure of the title compound, (I).

A view of the molecular structure of (I) is given in Fig. 1. Attempts to determine the absolute configuration of the molecule were inconclusive, but (I) can be assigned the illu-strated configuration since the chirality of the starting material is known. Furthermore, the conformation of the compound is essentially the same as the corresponding conformation of the crystal structure of (II) (Luo et al., 1984). Owing to the presence of the C C bond in (I), the C1—O1—C14 bond angle of 118.78 (15)_{is reduced from 124.2 (4), found for the}

corresponding angle in (II), while the C1—C2—C4 bond angle of 119.78 (17) _{is expanded from that of 115.3 (4) found in}

The six-membered ringA(C4–C7/C9/C15; scheme 1) has a slightly distorted chair conformation, with Cremer & Pople (1975) puckering parameters ofQ= 0.537 (2) A˚ , = 5.2 (2)

and’= 79 (2)_{. For an ideal chair,has a value of 0 or 180.}

By contrast, the corresponding six-membered ring in (II) has a normal chair conformation (Luo et al., 1984). The seven-membered ring B (C9–C12/O2/O3/C15) contains the key peroxy linkage [O2—O3 = 1.4670 (18) A˚ ]. The six-membered ring C(O2/O3/C15/C14/O4/C12) including an oxygen bridge and a peroxy bridge is best described by a twist–boat conformation, for which the puckering parameters,Q,and’, are 0.7441 (17) A˚ , 95.48 (12) _{and 155.61 (12), respectively.}

For an ideal twist–boat conformation, and ’ are 90 _and

(60n+ 30)_{, respectively. This conformation is consistent with}

those of artemisinin (Qinghaosu Research Group, 1980), (II), and artemether (Luoet al., 1984). The six-membered ringD

(O1/C1/C2/C4/C15/C14) has a double bond [C1 C2 = 1.314 (3) A˚ ]. It is best described by an envelope conformation, for which the puckering parameters, Q, and ’, are 0.4322 (18) A˚ , 53.4 (3) _{and 236.5 (3). For an ideal envelope}

conformation,and’are 54.7_{and 60n, respectively.}

Experimental

Compound (I) was prepared according to a literature procedure (Posner et al., 1997). To a solution of (II) (599 mg, 2.11 mmol) in toluene (60 ml) was added triethylene glycol (0.144 ml, 1.06 mmol) followed by BF3Et2O (0.064 ml, 0.53 mmol). The reaction was stirred

at room temperature for 3 h. The mixture was then diluted with CH2Cl2 and washed twice with water. The organic portion was

collected, dried over MgSO4and concentrated. The crude product

was purified by column chromatography (flash, 5–50% ethyl acetate/ hexane) to produce (I) (125 mg, yield 22.3%). Crystals were obtained from a hexane solution of (I) by slow evaporation at room temperature. Analysis calculated for C15H22O4: C 67.65, H 8.33%;

found: C 67.62, H 8.35%.

Crystal data

C15H22O4

Mr= 266.33

Orthorhombic,P212121

a= 6.2460 (12) A˚

b= 9.0416 (18) A˚

c= 25.132 (5) A˚

V= 1419.3 (5) A˚3

Z= 4

Dx= 1.246 Mg m 3

MoKradiation

= 0.09 mm 1

T= 295 (2) K Prism, colorless 0.360.250.18 mm

Data collection

Rigaku R-AXIS RAPID diffractometer

!scans

Absorption correction: multi-scan (ABSCOR; Higashi, 1995)

Tmin= 0.962,Tmax= 0.978

13861 measured reflections 1896 independent reflections 1658 reflections withI> 2(I)

Rint= 0.021

max= 27.4

Refinement

Refinement onF2

R[F2_{> 2(F}2_{)] = 0.035}

wR(F2) = 0.101

S= 1.09 1896 reflections 175 parameters

H-atom parameters constrained

w= 1/[2_(F

o2) + (0.0671P)2

+ 0.0449P] whereP= (Fo

2

+ 2Fc 2

)/3 (/)max< 0.001

max= 0.22 e A˚ 3 min= 0.11 e A˚ 3

The methyl H atoms were constrained to an ideal geometry [C— H = 0.96 A˚ , withUiso(H) = 1.5Ueq(C)] but were allowed to rotate

freely about the C—C bonds. All other H atoms were placed in geometrically idealized positions and constrained to ride on their parent C atoms at distances of 0.93, 0.97 or 0.98 A˚ for alkene, methylene or methine groups, respectively, and with Uiso(H) =

1.2Ueq(C). In the absence of significant anomalous scattering, Friedel

pairs were merged before the final refinement and the absolute configuration was assigned to correspond to that determined for artemisinin (Qinghaosu Research Group, 1980).

Data collection:RAPID-AUTO(Rigaku Corporation, 1998); cell refinement: RAPID-AUTO; data reduction: CrystalStructure

(Rigaku/MSC, 2002); program(s) used to solve structure:SHELXS97

(Sheldrick, 1997); program(s) used to refine structure:SHELXL97

(Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication:SHELXL97.

This work was supported by the National Natural Science Foundation of China (No. 20271018), the Natural Science Foundation of Heilongjiang Province (No. B0109), and the Outstanding Youth Foundation of Heilongjiang University (No. J200206).

References

Brossi, A., Venugopalan, B., Dominguez Gerpe, L., Yeh, H. J. C., Flippen-Anderson, J. L., Buchs, P., Luo, X. D., Milhous, W. & Peters, W. (1988).J. Med. Chem.31, 645–650.

Cremer, D. & Pople, J. A. (1975).J. Am. Chem. Soc.97, 1354–1358. Dominguez Gerpe, L., Yeh, H. J. C., Brossi, A. & Flippen-Anderson, J. L.

(1988).Heterocycles,27, 897–901.

El-Feraly, F. S., Ayalp, A., Al-Yahya, M. A., Mcphall, D. R. & Mcphall, A. T. (1990).J. Nat. Prod.53, 66–71.

Flippen-Anderson, J. L., George, C., Gilardi, R., Yu, Q. S., Dominguez, L. & Brossi, A. (1989).Acta Cryst.C45, 292–294.

Haynes, R. K., Chan, H. W., Cheung, M. K., Lam, W. L., Soo, M. K., Tsang, H. W., Voerste, A. & Williams, I. D. (2002).Eur. J. Org. Chem.1, 113–132. Higashi, T. (1995).ABSCOR. Rigaku Corporation, Tokyo, Japan.

Johnson, C. K. (1976).ORTEPII. Report ORNL-5138, Oak Ridge National Laboratory, Tennessee, USA.

organic papers

Acta Cryst.(2006). E62, o1898–o1900 Liet al. _C

15H22O4

o1899

Figure 1

Li, Y., Yu, P. L., Chen, Y. X., Li, L. Q., Gai, Y. Z., Wang, D. S. & Zheng, Y. P. (1981).Acta Pharm. Sin.16, 429–439.

Lin, A. J., Li, L. Q., Klayman, D. L., George, C. F. & Flippen-Anderson, J. L. (1990).J. Med. Chem.33, 2610–2614.

Luo, X. D., Yeh, H. J. C., Brossi, A., Flippen-Anderson, J. L. & Gilardi, R. (1984).Helv. Chim. Acta,67, 1515–1522.

Posner, G. H. & O’Neill, P. M. (2004).Acc. Chem. Res.37, 397–404. Posner, G. H., Ploypradith, P., Hapangama, W., Wang, D., Cumming, J. N.,

Dolan, P., Kensler, T. W., Klinedinst, D., Shapiro, T. A., Zheng, Q. Y.,

Murray, C. K., Pilkington, L. G., Jayasinghe, L. R., Bray, J. F. & Daughenbaugh, R. (1997).Bioorg. Med. Chem.5, 1257–1265.

Qinghaosu Research Group (1980).Sci. Sin. (Engl. Ed.),23, 380–396. Rigaku Corporation (1998). RAPID-AUTO. Rigaku Corporation, Tokyo,

Japan.

Rigaku/MSC (2002). CrystalStructure. Rigaku/MSC Inc., The Woodlands, Texas, USA.

Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Go¨ttingen, Germany.

organic papers

o1900

supporting information

sup-1 Acta Cryst. (2006). E62, o1898–o1900

supporting information

Acta Cryst. (2006). E62, o1898–o1900 [https://doi.org/10.1107/S1600536806013109]

9,10-Dehydrodeoxyartemisinin

Shu-Hui Li, Zheng-Yu Yue, Po Gao and Peng-Fei Yan

9,10-Dehydrodeoxyartemisinin

Crystal data C15H22O4

Mr = 266.33

Orthorhombic, P212121

Hall symbol: P 2ac 2ab a = 6.2460 (12) Å b = 9.0416 (18) Å c = 25.132 (5) Å V = 1419.3 (5) Å3

Z = 4

F(000) = 576 Dx = 1.246 Mg m−3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 12144 reflections θ = 3.3–27.4°

µ = 0.09 mm−1

T = 295 K Prism, colorless 0.36 × 0.25 × 0.18 mm

Data collection

Rigaku R-AXIS RAPID diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

Detector resolution: 10.000 pixels mm-1

ω scans

Absorption correction: multi-scan (ABSCOR; Higashi, 1995) Tmin = 0.962, Tmax = 0.978

13861 measured reflections 1896 independent reflections 1658 reflections with I > 2σ(I) Rint = 0.021

θmax = 27.4°, θmin = 3.2°

h = −6→8 k = −11→11 l = −32→32

Refinement Refinement on F2

Least-squares matrix: full R[F2 _{> 2σ(F}2_{)] = 0.035}

wR(F2_{) = 0.101}

S = 1.09 1896 reflections 175 parameters 0 restraints

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

Hydrogen site location: inferred from neighbouring sites

H-atom parameters constrained w = 1/[σ2_(F

o2) + (0.0671P)2 + 0.0449P]

where P = (Fo2 + 2Fc2)/3

(Δ/σ)max < 0.001

Δρmax = 0.22 e Å−3

Δρmin = −0.11 e Å−3

Special details

supporting information

sup-2 Acta Cryst. (2006). E62, o1898–o1900

Refinement. Refinement of F2 _{against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F}2_,

conventional R-factors R are based on F, with F set to zero for negative F2_{. The threshold expression of F}2 _{> σ(F}2_{) 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₎

x y z Uiso*/Ueq

O1 0.5740 (3) 0.57592 (14) 0.19525 (5) 0.0578 (4)

O2 0.9047 (2) 0.36439 (17) 0.18730 (5) 0.0553 (4)

O3 0.82582 (18) 0.35851 (16) 0.13236 (5) 0.0507 (3)

O4 0.5713 (2) 0.34360 (14) 0.22712 (4) 0.0451 (3)

C1 0.6289 (4) 0.6678 (2) 0.15433 (9) 0.0585 (5)

H1 0.6731 0.7628 0.1634 0.070*

C2 0.6254 (3) 0.6349 (2) 0.10339 (9) 0.0559 (5)

C3 0.6984 (6) 0.7434 (3) 0.06167 (11) 0.0882 (8)

H3A 0.7410 0.8341 0.0785 0.132*

H3B 0.5831 0.7627 0.0374 0.132*

H3C 0.8177 0.7027 0.0425 0.132*

C4 0.5542 (3) 0.4835 (2) 0.08580 (7) 0.0478 (4)

H4 0.6428 0.4549 0.0553 0.057*

C5 0.3192 (3) 0.4827 (2) 0.06747 (8) 0.0569 (5)

H5A 0.2287 0.5170 0.0963 0.068*

H5B 0.3023 0.5504 0.0378 0.068*

C6 0.2485 (4) 0.3297 (3) 0.05064 (7) 0.0594 (5)

H6A 0.3308 0.2992 0.0198 0.071*

H6B 0.0989 0.3329 0.0404 0.071*

C7 0.2776 (3) 0.2164 (2) 0.09480 (7) 0.0499 (4)

H7 0.1832 0.2446 0.1243 0.060*

C8 0.2079 (5) 0.0633 (3) 0.07545 (11) 0.0780 (7)

H8A 0.0665 0.0693 0.0606 0.117*

H8B 0.2077 −0.0045 0.1048 0.117*

H8C 0.3059 0.0290 0.0487 0.117*

C9 0.5094 (3) 0.21567 (18) 0.11603 (7) 0.0435 (4)

H9 0.5998 0.1784 0.0871 0.052*

C10 0.5330 (3) 0.1064 (2) 0.16236 (8) 0.0507 (4)

H10A 0.4131 0.1202 0.1864 0.061*

H10B 0.5234 0.0068 0.1482 0.061*

C11 0.7394 (3) 0.1190 (2) 0.19436 (8) 0.0531 (4)

H11A 0.8595 0.0972 0.1712 0.064*

H11B 0.7377 0.0452 0.2224 0.064*

C12 0.7736 (3) 0.2715 (2) 0.21945 (7) 0.0487 (4)

C13 0.8872 (4) 0.2674 (3) 0.27263 (9) 0.0679 (6)

H13A 1.0126 0.2065 0.2699 0.102*

H13B 0.7929 0.2273 0.2991 0.102*

H13C 0.9281 0.3659 0.2826 0.102*

C14 0.5086 (3) 0.42841 (18) 0.18326 (6) 0.0411 (4)

supporting information

sup-3 Acta Cryst. (2006). E62, o1898–o1900

C15 0.5940 (2) 0.37081 (18) 0.13012 (6) 0.0394 (3)

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

O1 0.0830 (10) 0.0412 (6) 0.0491 (7) 0.0018 (7) −0.0046 (7) −0.0016 (5)

O2 0.0394 (6) 0.0659 (8) 0.0607 (8) −0.0025 (7) −0.0076 (6) 0.0142 (7)

O3 0.0337 (6) 0.0678 (8) 0.0506 (7) 0.0059 (6) 0.0046 (5) 0.0098 (6)

O4 0.0483 (6) 0.0485 (6) 0.0384 (6) 0.0019 (6) −0.0002 (5) 0.0029 (5)

C1 0.0635 (12) 0.0418 (9) 0.0702 (12) −0.0020 (9) −0.0099 (10) 0.0103 (8)

C2 0.0557 (10) 0.0514 (9) 0.0607 (11) 0.0008 (9) −0.0038 (9) 0.0167 (9)

C3 0.105 (2) 0.0755 (15) 0.0839 (17) −0.0142 (17) 0.0030 (16) 0.0338 (13)

C4 0.0466 (9) 0.0549 (9) 0.0419 (8) 0.0033 (8) 0.0041 (8) 0.0090 (7)

C5 0.0541 (10) 0.0654 (11) 0.0512 (10) 0.0093 (9) −0.0086 (9) 0.0120 (9)

C6 0.0537 (10) 0.0813 (13) 0.0433 (9) 0.0029 (11) −0.0079 (8) 0.0000 (9)

C7 0.0462 (9) 0.0581 (10) 0.0453 (9) −0.0001 (8) 0.0008 (8) −0.0063 (8)

C8 0.0845 (17) 0.0728 (14) 0.0766 (14) −0.0150 (14) −0.0167 (14) −0.0125 (12)

C9 0.0427 (9) 0.0472 (8) 0.0406 (8) 0.0067 (7) 0.0061 (7) −0.0051 (7)

C10 0.0572 (11) 0.0403 (8) 0.0546 (10) 0.0011 (8) −0.0001 (9) −0.0006 (7)

C11 0.0529 (10) 0.0483 (9) 0.0581 (10) 0.0114 (9) −0.0008 (9) 0.0088 (8)

C12 0.0415 (8) 0.0536 (9) 0.0511 (9) 0.0013 (8) −0.0062 (8) 0.0105 (8)

C13 0.0649 (12) 0.0733 (13) 0.0655 (12) −0.0077 (12) −0.0231 (11) 0.0151 (10)

C14 0.0410 (8) 0.0423 (8) 0.0401 (8) 0.0036 (7) 0.0012 (6) 0.0003 (6)

C15 0.0327 (7) 0.0461 (8) 0.0395 (8) 0.0056 (7) 0.0040 (6) 0.0038 (7)

Geometric parameters (Å, º)

O1—C1 1.366 (2) C6—H6B 0.9700

O1—C14 1.427 (2) C7—C8 1.531 (3)

O2—C12 1.424 (2) C7—C9 1.543 (3)

O2—O3 1.4670 (18) C7—H7 0.9800

O3—C15 1.4536 (19) C8—H8A 0.9600

O4—C14 1.3989 (19) C8—H8B 0.9600

O4—C12 1.434 (2) C8—H8C 0.9600

C1—C2 1.314 (3) C9—C10 1.534 (2)

C1—H1 0.9300 C9—C15 1.540 (2)

C2—C4 1.506 (3) C9—H9 0.9800

C2—C3 1.507 (3) C10—C11 1.523 (3)

C3—H3A 0.9600 C10—H10A 0.9700

C3—H3B 0.9600 C10—H10B 0.9700

C3—H3C 0.9600 C11—C12 1.531 (3)

C4—C15 1.530 (2) C11—H11A 0.9700

C4—C5 1.538 (3) C11—H11B 0.9700

C4—H4 0.9800 C12—C13 1.514 (3)

C5—C6 1.512 (3) C13—H13A 0.9600

C5—H5A 0.9700 C13—H13B 0.9600

C5—H5B 0.9700 C13—H13C 0.9600

supporting information

sup-4 Acta Cryst. (2006). E62, o1898–o1900

C6—H6A 0.9700 C14—H14 0.9800

C1—O1—C14 118.78 (15) H8A—C8—H8C 109.5

C12—O2—O3 108.63 (13) H8B—C8—H8C 109.5

C15—O3—O2 111.60 (12) C10—C9—C15 112.28 (14)

C14—O4—C12 112.95 (13) C10—C9—C7 110.82 (15)

C2—C1—O1 126.26 (19) C15—C9—C7 113.42 (14)

C2—C1—H1 116.9 C10—C9—H9 106.6

O1—C1—H1 116.9 C15—C9—H9 106.6

C1—C2—C4 119.78 (17) C7—C9—H9 106.6

C1—C2—C3 121.7 (2) C11—C10—C9 115.70 (16)

C4—C2—C3 118.5 (2) C11—C10—H10A 108.4

C2—C3—H3A 109.5 C9—C10—H10A 108.4

C2—C3—H3B 109.5 C11—C10—H10B 108.4

H3A—C3—H3B 109.5 C9—C10—H10B 108.4

C2—C3—H3C 109.5 H10A—C10—H10B 107.4

H3A—C3—H3C 109.5 C10—C11—C12 113.76 (15)

H3B—C3—H3C 109.5 C10—C11—H11A 108.8

C2—C4—C15 110.11 (15) C12—C11—H11A 108.8

C2—C4—C5 111.96 (17) C10—C11—H11B 108.8

C15—C4—C5 111.69 (15) C12—C11—H11B 108.8

C2—C4—H4 107.6 H11A—C11—H11B 107.7

C15—C4—H4 107.6 O2—C12—O4 108.35 (14)

C5—C4—H4 107.6 O2—C12—C13 104.22 (16)

C6—C5—C4 111.51 (18) O4—C12—C13 107.77 (17)

C6—C5—H5A 109.3 O2—C12—C11 112.18 (16)

C4—C5—H5A 109.3 O4—C12—C11 109.98 (15)

C6—C5—H5B 109.3 C13—C12—C11 114.02 (16)

C4—C5—H5B 109.3 C12—C13—H13A 109.5

H5A—C5—H5B 108.0 C12—C13—H13B 109.5

C5—C6—C7 112.15 (15) H13A—C13—H13B 109.5

C5—C6—H6A 109.2 C12—C13—H13C 109.5

C7—C6—H6A 109.2 H13A—C13—H13C 109.5

C5—C6—H6B 109.2 H13B—C13—H13C 109.5

C7—C6—H6B 109.2 O4—C14—O1 105.40 (13)

H6A—C6—H6B 107.9 O4—C14—C15 113.81 (13)

C6—C7—C8 110.08 (17) O1—C14—C15 113.75 (14)

C6—C7—C9 111.54 (16) O4—C14—H14 107.9

C8—C7—C9 111.90 (18) O1—C14—H14 107.9

C6—C7—H7 107.7 C15—C14—H14 107.9

C8—C7—H7 107.7 O3—C15—C14 109.87 (14)

C9—C7—H7 107.7 O3—C15—C4 103.92 (13)

C7—C8—H8A 109.5 C14—C15—C4 110.63 (13)

C7—C8—H8B 109.5 O3—C15—C9 106.31 (14)

H8A—C8—H8B 109.5 C14—C15—C9 113.03 (14)

C7—C8—H8C 109.5 C4—C15—C9 112.56 (14)

supporting information

sup-5 Acta Cryst. (2006). E62, o1898–o1900

C14—O1—C1—C2 1.0 (3) C10—C11—C12—C13 146.47 (18)

O1—C1—C2—C4 0.4 (4) C12—O4—C14—O1 −96.29 (16)

O1—C1—C2—C3 −177.4 (2) C12—O4—C14—C15 29.0 (2)

C1—C2—C4—C15 −26.1 (3) C1—O1—C14—O4 149.55 (17)

C3—C2—C4—C15 151.8 (2) C1—O1—C14—C15 24.2 (2)

C1—C2—C4—C5 98.8 (2) O2—O3—C15—C14 15.61 (18)

C3—C2—C4—C5 −83.3 (3) O2—O3—C15—C4 134.01 (14)

C2—C4—C5—C6 −179.19 (16) O2—O3—C15—C9 −107.02 (15)

C15—C4—C5—C6 −55.2 (2) O4—C14—C15—O3 −55.39 (19)

C4—C5—C6—C7 57.1 (2) O1—C14—C15—O3 65.36 (18)

C5—C6—C7—C8 −178.9 (2) O4—C14—C15—C4 −169.56 (14)

C5—C6—C7—C9 −54.1 (2) O1—C14—C15—C4 −48.8 (2)

C6—C7—C9—C10 177.18 (15) O4—C14—C15—C9 63.18 (19)

C8—C7—C9—C10 −59.0 (2) O1—C14—C15—C9 −176.07 (14)

C6—C7—C9—C15 49.82 (19) C2—C4—C15—O3 −69.53 (19)

C8—C7—C9—C15 173.64 (18) C5—C4—C15—O3 165.42 (16)

C15—C9—C10—C11 −39.4 (2) C2—C4—C15—C14 48.3 (2)

C7—C9—C10—C11 −167.39 (15) C5—C4—C15—C14 −76.7 (2)

C9—C10—C11—C12 58.7 (2) C2—C4—C15—C9 175.86 (15)

O3—O2—C12—O4 −73.64 (17) C5—C4—C15—C9 50.8 (2)

O3—O2—C12—C13 171.79 (15) C10—C9—C15—O3 71.56 (17)

O3—O2—C12—C11 47.95 (18) C7—C9—C15—O3 −161.85 (13)

C14—O4—C12—O2 33.15 (19) C10—C9—C15—C14 −49.05 (19)

C14—O4—C12—C13 145.37 (16) C7—C9—C15—C14 77.54 (17)

C14—O4—C12—C11 −89.79 (17) C10—C9—C15—C4 −175.30 (14)