5 Hydro­xy 3,3′,4′,5′,7 penta­meth­oxy­flavone (combretol)

organic papers

o86

Acta Crystallographica Section E Structure Reports Online

ISSN 1600-5368

5-Hydroxy-3,3

_,4

_,5

_{,7-pentamethoxyflavone}

(combretol)

Dachriyanus,a_{Rizal Fahmi,}b

Melvyn V. Sargent,c_{Brian W.}

Skeltonc_{* and Allan H. White}c

a_{Jurusan Farmasi, FMIPA, Universitas Andalas,}

Padang, West Sumatra, Indonesia,b_Jurusan

Kimia, FMIPA, Universitas Andalas, Padang, West Sumatra, Indonesia, andc_{Department of}

Chemistry, University of Western Australia, Crawley, WA 6009, Australia

Correspondence e-mail: bws@crystal.uwa.edu.au

Correspondence e-mail: bws@crystal.uwa.edu.au

Correspondence e-mail: bws@crystal.uwa.edu.au

Correspondence e-mail: bws@crystal.uwa.edu.au

Correspondence e-mail: bws@crystal.uwa.edu.au

Key indicators Single-crystal X-ray study

T= 150 K

Mean(C±C) = 0.009 AÊ

Rfactor = 0.053

wRfactor = 0.059 Data-to-parameter ratio = 6.1

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

#2004 International Union of Crystallography Printed in Great Britain ± all rights reserved

The structure of the title compound, C20H20O8, which was extracted fromRhodomyrtus tomentosa, con®rms the connec-tivity and is consistent with the results from spectroscopy. The structure, notable for the crowded sequence of (30_,40_,50₎

trimethoxy substituents, is compared with that of its previously recorded analogue lacking the methyl at the 40_{-oxygen (two}

polymorphs), and with myricetin which lacks all O -methyl-ation (cocrystallized with triphenylphosphine oxide). The latter, interestingly, has a dihedral angle of 36.4 (3)_between

its planar aromatic components, but the overall cyclic frame-work of the title molecule is essentially planar. In the crystal structure, the molecules stack obliquely along the short [4.244 (2) AÊ]caxis of the orthogonal cell.

Comment

In continuation of our studies on the constituents of Rhodo-myrtus tomentosa (Ait.) Hassk.(Dachriyanuset al., 2002), the bark and twigs of this plant were investigated. The ethyl acetate fraction of the extract of these parts showed signi®cant antimicrobial activity. From this fraction the ¯avonol combretol, (1) (3,30_,40_,50_{,7-penta-O-methylmyricetin), was}

isolated. The crystal structure determination and full NMR assignment of this compound are reported.

Compound (1) crystallized in space group Pna21, one formula unit devoid of crystallographic symmetry comprising the asymmetric unit of the structure which, although non-centrosymmetric, is racemic (Fig. 1). Consisting as it does of extended planar aromatic motifs, it is unsurprizing to ®nd the molecules packing with these planes quasi-normal to a short crystallographic axis (Fig. 2) with, presumably, charge-transfer interactions a signi®cant factor in the stacking. The interplanar dihedral angle between the two aromatic ring systems (O1/C2/ C3/C4/C4a/C5/C6/C7/C8/C8a and C10_±C60_{) is 6.8 (3), these}

being closely coplanar. This is also the case in the two poly-morphs of the variation on (1), compound (2), lacking the methyl at the 40_{-oxygen, in which the dihedral angles are 7.8 (}

polymorph) and 0.4_{( polymorph) (Castledenet al., 1985).}

These contrast with related hydroxylated species such as myricetin, (3) (cocrystallized with triphenylphosphine oxide), in which the angle is 36.4 (3)_{(Cody & Luft, 1994) and, further}

a®eld, in morin monohydrate (Cody & Luft, 1994) where the

angles are 41.63 (8) and 48.31 (8) _{(two molecules). In the}

latter, intermolecular hydrogen bonding contributes exten-sively to the structures, but in (2) which is highly methylated, and even more so in (1), for such phenolic residues as remain, intramolecular interactions predominate; here H5 O4 is 1.70 AÊ. As in (2), most of the methoxy substituents lie coplanar with their associated ring systems; exceptions are found for substituents 3 in each of (1) and (2) and in the present (1) the substituent at 40 _{is also out-of-plane, all for}

steric reasons. Substantial asymmetries are found in the exocyclic angles at C2 and C10_{, with H2}0 _{O3 and H6}0 _{O1 =}

2.16 and 2.30 AÊ and C2ÐC10 _{= 1.454 AÊ. Bond lengths and}

angles otherwise are in substantial agreement between (1) and (2), but between these and, for example, (3), unsurprisingly, much more substantial differences are found.

Experimental

General procedures have been described previously (Baker et al., 2000).Rhodomyrtus tomentosawas collected at Andalas University Campus, Limau Manis, Padang, West Sumatra, Indonesia in December 2001. A voucher specimen (DR-180) was identi®ed by Dr Rusjdi Tamin. The ground air-dried bark and twigs (500 g) were defatted with hexane (32 l) and then extracted with ethyl acetate (32 l). The ethyl acetate extract was evaporatedin vacuoto give a yellow gum (9 g). This fraction showed a signi®cant antimicrobial activity. A portion of the ethyl acetate fraction (5 g) was preadsorbed on to silica gel and chromatographed over a column of silica gel with increasing amounts of ethyl acetate in hexane as eluent. Fractions which exhibited a similar pattern on thin-layer chromatography were combined and subjected to radial chromatography to give combretol, (1) (60 mg), which crystallized from ethyl acetate/hexane as yellow needles, m.p. 419±420 K (417 K; Mongkolsuket al., 1966).

Found: [M]+_{388.1156; C}

20H20O8requires 388.1158; IR (KBr)max:

3419, 1666, 1661, 1590, 1500, 1456, 1246, 1213, 1167, 1162, 1136, 1128 cmÿ1_{; UV}

max(CH3OH): 209 ("44,000), 267 ("15,800), 344 ("

14,900);1_{H NMR (500 MHz, CDCl}

3):3.861 (s, 3H, C-3 OMe), 3.864

(s, 3H, C-7 OMe), 3.932 (s, 6H, C-30_{and 5}0_{2OMe), 3.935 (s, 3H,}

C-40 _{OMe), 6.34 (d,J}

6,7= 2.2 Hz, 1 H, 6H), 6.43 (d,J7,6= 2.2 Hz, 1H,

7H), 7.35 (s, 2H, 20_{and 6}0_{H), 12.56 (s, 1H, 5-OH)}13_{C NMR (125 MHz,}

CDCl3):55.79 (C-7, OMe), 56.28 (C-30 and 50, OMe), 60.27 (C-3,

OMe), 60.95 (C-40_{, OMe), 92.18 (C-8), 97.87 (C-6), 106.00 (C-10, -2}0

and -60_{), 125.40 (C-1}0_{), 139.34 (C-3), 140.54 (C-4}0_{), 153.06 (C-3}0 _and

50_{), 155.53 2), 156.65 9), 161.96 5), 165.51 7), 178.70}

(C-4); MSm/z(rel. int.): 388 [M]+_{(100), 373 [M-CH}

3] (75), 345 (37).

Crystal data

C20H20O8

Mr= 388.37

Orthorhombic,Pna21

a= 13.827 (6) AÊ

b= 29.900 (14) AÊ

c= 4.244 (2) AÊ

V= 1754.6 (14) AÊ3

Z= 4

Dx= 1.47 Mg mÿ3

Mo Kradiation Cell parameters from 1050

re¯ections

= 2.4±24.5 = 0.12 mmÿ1

T= 150 (2) K

Splinter, colourless yellow 0.300.060.03 mm

Data collection

Bruker SMART CCD diffractometer

!scans

Absorption correction: multi-scan

SADABS; Sheldrick, 1996

Tmin= 0.957,Tmax= 0.998 13745 measured re¯ections

1789 independent re¯ections 1526 re¯ections withI>(I)

Rint= 0.077 max= 25.2

h=ÿ16!16

k=ÿ35!35

l=ÿ5!5

Acta Cryst.(2004). E60, o86±o88 Dachriyanuset al. C₂₀H₂₀O₈

o87

organic papers

Figure 1

Projection of a single molecule of (1), showing 50% probability displacement ellipsoids for the non-H atoms. H atoms have arbitrary radii of 0.1 AÊ.

Figure 2

organic papers

o88

Re®nement

Re®nement onF R= 0.053

wR= 0.059

S= 1.14 1526 re¯ections 252 parameters

H-atom parameters constrained

w= 1/[2_(F

o) + 0.0013F2]

where(I) = [(I)meas+ 0.0004(Inet)2]1/2 (/)max= 0.009 max= 0.37 e AÊÿ3 min=ÿ0.36 e AÊÿ3

Table 1

Selected geometric parameters (AÊ,_).

O1ÐC2 1.382 (8)

O1ÐC8a 1.348 (7)

C2ÐC10 _{1.454 (9)}

C3ÐO3 1.381 (10)

O3ÐC31 1.461 (9)

C4ÐO4 1.267 (8)

C5ÐO5 1.370 (8)

C7ÐO7 1.359 (9)

O7ÐC71 1.447 (7)

C30_ÐO30 _{1.361 (9)}

O30_ÐC310 _{1.439 (9)}

C40_ÐO40 _{1.363 (8)}

C50_ÐO50 _{1.396 (8)}

C2ÐO1ÐC8a 122.5 (5)

O1ÐC2ÐC3 118.6 (6)

O1ÐC2ÐC10 _{111.6 (5)}

C3ÐC2ÐC10 _{129.7 (7)}

C3ÐC4ÐO4 122.2 (7)

C4aÐC5ÐO5 119.6 (6)

C6ÐC7ÐO7 113.6 (6)

C7ÐO7ÐC71 116.6 (5)

C20_ÐC30_ÐO30 _{125.8 (6)}

C30_ÐO30_ÐC310 _{117.0 (5)}

C30_ÐC40_ÐO40 _{120.5 (6)}

C40_ÐO40_ÐC410 _{113.4 (6)}

O50_ÐC50_ÐC60 _{123.6 (7)}

C50_ÐO50_ÐC510 _{116.9 (5)}

The H atoms were located in difference Fourier maps, and placed at idealized positions; CÐH = 0.95 AÊ, andUiso(H) = 1.25Ueq(C) (CH)

and 1.5Ueq(C) (CH3and OH).

Data collection:SMART(Siemens, 1995); cell re®nement:SAINT (Siemens, 1995); data reduction: Xtal3.5 (Hall et al., 1995); program(s) used to solve structure:Xtal3.5; program(s) used to re®ne structure: Xtal3.5 CRYLSQ; molecular graphics: Xtal3.5; software used to prepare material for publication:Xtal3.5BONDLA CIFIO.

We thank Dr Rusjdi Tamin for the identi®cation of the plant material and UNESCO for a travel grant.

References

Baker, R. W., Brkic, Z., Sargent, M. V., Skelton, B. W. & White, A. H. (2000).

Aust. J. Chem.53, 925±938.

Castleden, I. R., Hall, S. R., Nimgiriwath, S., Thadaniti, S. & White, A. H. (1985).Aust. J. Chem.38, 1177±85.

Cody, V. & Luft, J. R. (1994).J. Mol. Struct.317, 89±97.

Dachriyanus, Salni, Sargent, M. V., Skelton, B. W., Soediro, I., Sutrisna, M., White, A. H. & Yulinah, E. (2002).Aust. J. Chem.55, 229±232.

Hall, S. R., King, G. S. D. & Stewart, J. M. (1995). Editors. Xtal3.5Users Manual.University of Western Australia, Australia.

Mongkolsuk, S., Dean, F. M. & Houghton, L. E. (1966).J. Chem. Soc. C, p. 125. Sheldrick, G M. (1996).SADABS. University of GoÈttingen, Germany. Siemens (1995).SMARTandSAINT. Siemens Analytical X-ray Instruments

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Acta Cryst. (2004). E60, o86–o88

supporting information

Acta Cryst. (2004). E60, o86–o88 [https://doi.org/10.1107/S1600536803027880]

5-Hydroxy-3,3

′

,4

′

,5

′

,7-pentamethoxyflavone (combretol)

Dachriyanus, Rizal Fahmi, Melvyn V. Sargent, Brian W. Skelton and Allan H. White

(1)

Crystal data C20H20O8

Mr = 388.37

Orthorhombic, Pna21

Hall symbol: P 2c -2n a = 13.827 (6) Å b = 29.900 (14) Å c = 4.244 (2) Å V = 1754.6 (14) Å3

Z = 4

F(000) = 816 Dx = 1.47 Mg m−3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 1050 reflections θ = 2.4–24.5°

µ = 0.12 mm−1

T = 150 K Splinter, yellow 0.3 × 0.06 × 0.03 mm

Data collection Bruker SMART CCD

diffractometer

Radiation source: sealed tube Graphite monochromator ω scans

Absorption correction: multi-scan SADABS; Sheldrick, 1996 Tmin = 0.957, Tmax = 0.998

13745 measured reflections 1789 independent reflections 1526 reflections with I > σ(I) Rint = 0.077

θmax = 25.2°, θmin = 1.4°

h = −16→16 k = −35→35 l = −5→5

Refinement Refinement on F

Least-squares matrix: full R[F2 _{> 2σ(F}2_{)] = 0.053}

wR(F2_{) = 0.059}

S = 1.06 1526 reflections 252 parameters 0 restraints 0 constraints

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

Hydrogen site location: difference Fourier map H-atom parameters not refined

w = 1/[σ2_(F

o) + 0.0013F2]

where σ(I) = [σ(I)meas + 0.0004(Inet)2]1/2

(Δ/σ)max = 0.009

Δρmax = 0.37 e Å−3

Δρmin = −0.36 e Å−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2₎

x y z Uiso*/Ueq

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Acta Cryst. (2004). E60, o86–o88

O3 0.6037 (3) 0.20226 (12) 0.019 (2) 0.041 (3) C31 0.5771 (5) 0.24460 (19) 0.168 (3) 0.061 (5) C4 0.7449 (5) 0.18179 (19) 0.319 (2) 0.034 (4) O4 0.7892 (3) 0.21698 (13) 0.236 (2) 0.050 (3) C4a 0.7925 (4) 0.14885 (17) 0.512 (2) 0.031 (4) C5 0.8870 (5) 0.15326 (19) 0.621 (2) 0.036 (4) O5 0.9390 (3) 0.19077 (13) 0.546 (2) 0.054 (3) C6 0.9305 (4) 0.1201 (2) 0.794 (2) 0.035 (4) C7 0.8784 (5) 0.08063 (19) 0.862 (2) 0.032 (4) O7 0.9301 (3) 0.05004 (12) 1.029 (2) 0.042 (3) C71 0.8823 (5) 0.00809 (18) 1.097 (3) 0.048 (5) C8 0.7850 (4) 0.07549 (18) 0.765 (2) 0.034 (4) C8a 0.7409 (4) 0.10933 (19) 0.590 (2) 0.032 (4) C1′ 0.4999 (5) 0.12145 (19) 0.263 (2) 0.033 (4) C2′ 0.4361 (5) 0.14687 (18) 0.074 (3) 0.036 (4) C3′ 0.3412 (5) 0.13520 (19) 0.040 (2) 0.033 (4) O3′ 0.2736 (3) 0.15831 (13) −0.1267 (19) 0.047 (3) C31′ 0.3046 (5) 0.1992 (2) −0.274 (3) 0.051 (5) C4′ 0.3052 (5) 0.09560 (19) 0.185 (2) 0.037 (4) O4′ 0.2120 (3) 0.08239 (12) 0.1372 (19) 0.040 (3) C41′ 0.1442 (5) 0.1029 (2) 0.352 (3) 0.046 (5) C5′ 0.3683 (4) 0.07053 (19) 0.365 (2) 0.033 (4) O5′ 0.3261 (3) 0.03256 (13) 0.498 (2) 0.042 (3) C51′ 0.3856 (5) 0.0058 (2) 0.689 (3) 0.040 (4) C6′ 0.4634 (4) 0.08254 (18) 0.411 (2) 0.033 (4)

H31a 0.54480 0.26400 0.01704 0.09500*

H31b 0.63124 0.25988 0.24830 0.09500*

H31c 0.53151 0.23970 0.33717 0.09500*

H5 0.89591 0.20746 0.42162 0.08100*

H6 0.99720 0.12394 0.86810 0.04100*

H71a 0.92357 −0.01130 1.21786 0.07500*

H71b 0.86464 −0.00727 0.90812 0.07500*

H71c 0.82422 0.01278 1.21842 0.07500*

H8 0.75019 0.04898 0.82284 0.04000*

H2′ 0.46216 0.17279 −0.03682 0.04700*

H31'a 0.25485 0.21321 −0.38882 0.07100* H31'b 0.35761 0.19297 −0.42374 0.07100* H31'c 0.33059 0.21971 −0.12307 0.07100*

H41'a 0.07984 0.09278 0.30520 0.06200*

H41'b 0.14534 0.13478 0.32682 0.06200*

H41'c 0.15937 0.09562 0.56224 0.06200*

H51'a 0.35158 −0.01870 0.77682 0.06200*

H51'b 0.41060 0.02352 0.86719 0.06200*

H51'c 0.44056 −0.00480 0.57689 0.06200*

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Acta Cryst. (2004). E60, o86–o88

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

O1 0.030 (2) 0.023 (2) 0.051 (3) −0.0044 (18) −0.006 (3) 0.003 (3) C2 0.040 (4) 0.022 (3) 0.038 (5) 0.009 (3) −0.000 (4) −0.006 (4) C3 0.034 (4) 0.025 (3) 0.038 (5) 0.006 (3) −0.000 (4) −0.000 (4) O3 0.047 (3) 0.020 (2) 0.056 (4) −0.000 (2) −0.005 (3) 0.001 (3) C31 0.061 (5) 0.022 (3) 0.100 (8) 0.004 (3) −0.013 (6) −0.004 (5) C4 0.040 (4) 0.023 (3) 0.039 (5) −0.000 (3) 0.005 (4) −0.006 (4) O4 0.049 (3) 0.025 (2) 0.076 (4) −0.006 (2) −0.003 (3) 0.008 (3) C4a 0.034 (4) 0.019 (3) 0.041 (5) −0.003 (3) 0.009 (4) −0.004 (4) C5 0.033 (4) 0.024 (3) 0.052 (5) −0.001 (3) 0.000 (4) −0.009 (4) O5 0.044 (3) 0.032 (2) 0.085 (4) −0.016 (2) −0.011 (4) 0.013 (3) C6 0.028 (4) 0.034 (3) 0.044 (5) −0.003 (3) −0.001 (4) −0.006 (4) C7 0.033 (4) 0.028 (3) 0.034 (5) 0.002 (3) −0.004 (4) −0.002 (4) O7 0.036 (3) 0.028 (2) 0.061 (4) −0.003 (2) −0.005 (3) 0.003 (3) C71 0.042 (4) 0.020 (3) 0.081 (7) −0.002 (3) −0.002 (5) 0.007 (4) C8 0.028 (4) 0.021 (3) 0.051 (5) 0.000 (3) −0.001 (4) −0.001 (4) C8a 0.031 (4) 0.026 (3) 0.039 (5) −0.002 (3) −0.002 (3) −0.005 (4) C1′ 0.029 (4) 0.026 (3) 0.044 (5) 0.003 (3) −0.002 (4) −0.006 (4) C2′ 0.034 (4) 0.023 (3) 0.051 (5) −0.001 (3) −0.007 (4) 0.001 (4) C3′ 0.039 (4) 0.024 (3) 0.037 (5) 0.006 (3) −0.014 (4) −0.004 (4) O3′ 0.054 (3) 0.024 (2) 0.062 (4) −0.003 (2) −0.012 (3) 0.009 (3) C31′ 0.061 (5) 0.030 (4) 0.062 (6) 0.009 (3) −0.005 (5) 0.003 (5) C4′ 0.038 (4) 0.026 (3) 0.047 (5) −0.003 (3) −0.003 (4) −0.009 (4) O4′ 0.029 (3) 0.031 (2) 0.059 (4) −0.0015 (19) −0.009 (3) −0.006 (3) C41′ 0.030 (4) 0.041 (4) 0.068 (6) −0.002 (3) −0.001 (4) −0.004 (4) C5′ 0.032 (4) 0.023 (3) 0.043 (5) 0.003 (3) 0.002 (4) −0.005 (4) O5′ 0.033 (3) 0.033 (2) 0.060 (4) −0.003 (2) −0.005 (3) 0.008 (3) C51′ 0.040 (4) 0.030 (3) 0.049 (5) −0.004 (3) −0.003 (4) 0.005 (4) C6′ 0.033 (4) 0.016 (3) 0.049 (6) 0.006 (3) −0.002 (4) −0.001 (3)

Geometric parameters (Å, º)

O1—C2 1.382 (8) C8—C8a 1.396 (10)

O1—C8a 1.348 (7) C8—H8 0.959

C2—C3 1.380 (9) C1′—C2′ 1.414 (11)

C2—C1′ 1.454 (9) C1′—C6′ 1.415 (9)

C3—O3 1.381 (10) C2′—C3′ 1.365 (9)

C3—C4 1.423 (9) C2′—H2′ 0.976

O3—C31 1.461 (9) C3′—O3′ 1.361 (9)

C31—H31a 0.971 C3′—C4′ 1.425 (10)

C31—H31b 0.942 O3′—C31′ 1.439 (9)

C31—H31c 0.968 C31′—H31'a 0.940

C4—O4 1.267 (8) C31′—H31'b 0.987

C4—C4a 1.442 (10) C31′—H31'c 0.958

C4a—C5 1.391 (9) C4′—O4′ 1.363 (8)

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Acta Cryst. (2004). E60, o86–o88

C5—O5 1.370 (8) O4′—C41′ 1.444 (10)

C5—C6 1.374 (10) C41′—H41'a 0.961

O5—H5 0.939 C41′—H41'b 0.960

C6—C7 1.412 (9) C41′—H41'c 0.941

C6—H6 0.982 C5′—O5′ 1.396 (8)

C7—O7 1.359 (9) C5′—C6′ 1.377 (9)

C7—C8 1.363 (9) O5′—C51′ 1.405 (10)

O7—C71 1.447 (7) C51′—H51'a 0.946

C71—H71a 0.962 C51′—H51'b 0.985

C71—H71b 0.955 C51′—H51'c 0.952

C71—H71c 0.964 C6′—H6′ 0.985

C2—O1—C8a 122.5 (5) O1—C8a—C8 118.4 (5)

O1—C2—C3 118.6 (6) C4a—C8a—C8 120.5 (6)

O1—C2—C1′ 111.6 (5) C2—C1′—C2′ 122.5 (6)

C3—C2—C1′ 129.7 (7) C2—C1′—C6′ 119.4 (7)

C2—C3—O3 119.5 (6) C2′—C1′—C6′ 118.1 (6)

C2—C3—C4 122.1 (7) C1′—C2′—C3′ 121.5 (7)

O3—C3—C4 118.4 (6) C1′—C2′—H2′ 118.0

C3—O3—C31 113.2 (8) C3′—C2′—H2′ 120.5

O3—C31—H31a 110.5 C2′—C3′—O3′ 125.8 (6)

O3—C31—H31b 112.1 C2′—C3′—C4′ 120.2 (7)

O3—C31—H31c 110.7 O3′—C3′—C4′ 114.0 (6)

H31a—C31—H31b 108.4 C3′—O3′—C31′ 117.0 (5)

H31a—C31—H31c 106.3 O3′—C31′—H31'a 112.7

H31b—C31—H31c 108.7 O3′—C31′—H31'b 109.9

C3—C4—O4 122.2 (7) O3′—C31′—H31'c 111.3

C3—C4—C4a 117.5 (6) H31'a—C31′—H31'b 107.2 O4—C4—C4a 120.3 (6) H31'a—C31′—H31'c 109.6 C4—C4a—C5 123.5 (6) H31'b—C31′—H31'c 105.8 C4—C4a—C8a 118.1 (6) C3′—C4′—O4′ 120.5 (6) C5—C4a—C8a 118.3 (6) C3′—C4′—C5′ 118.0 (6)

C4a—C5—O5 119.6 (6) O4′—C4′—C5′ 121.5 (6)

C4a—C5—C6 121.3 (6) C4′—O4′—C41′ 113.4 (6)

O5—C5—C6 119.1 (6) O4′—C41′—H41'a 109.7

C5—O5—H5 103.4 O4′—C41′—H41'b 109.9

C5—C6—C7 119.3 (6) O4′—C41′—H41'c 110.9

C5—C6—H6 119.9 H41'a—C41′—H41'b 107.7

C7—C6—H6 120.8 H41'a—C41′—H41'c 109.3

C6—C7—O7 113.6 (6) H41'b—C41′—H41'c 109.4

C6—C7—C8 121.1 (6) C4′—C5′—O5′ 113.7 (5)

O7—C7—C8 125.4 (6) C4′—C5′—C6′ 122.7 (6)

C7—O7—C71 116.6 (5) O5′—C5′—C6′ 123.6 (7)

O7—C71—H71a 111.0 C5′—O5′—C51′ 116.9 (5)

O7—C71—H71b 111.4 O5′—C51′—H51'a 112.2

O7—C71—H71c 111.2 O5′—C51′—H51'b 110.0

H71a—C71—H71b 108.0 O5′—C51′—H51'c 111.5

supporting information

sup-5

Acta Cryst. (2004). E60, o86–o88

H71b—C71—H71c 107.8 H51'a—C51′—H51'c 109.6 C7—C8—C8a 119.5 (6) H51'b—C51′—H51'c 106.4

C7—C8—H8 119.5 C1′—C6′—C5′ 119.4 (7)

C8a—C8—H8 121.0 C1′—C6′—H6′ 120.1