(IUCr) Alpinumisoflavone

Volume 64
Part 4
Page o713
April 2008

Received 16 January 2008
Accepted 11 March 2008
Online 14 March 2008

Key indicators
Single-crystal X-ray study
T = 93 K
Mean (C-C) = 0.001 Å
R = 0.043
wR = 0.124
Data-to-parameter ratio = 19.7
Details

Alpinumisoflavone

Jerry Joe Ebow Kingsley Harrison,^a Youhei Tabuchi,^b Hiroyuki Ishida ^b and Robert Kingsford-Adaboh ^a ^*

^aDepartment of Chemistry, Faculty of Science, University of Ghana, Box LG56 Legon, Accra, Ghana, and ^bDepartment of Chemistry, Faculty of Science, Okayama University, Okayama 700-8530, Japan
Correspondence e-mail: kadabohs@ug.edu.gh

The title compound, C₂₀H₁₆O₅, {systematic name: 5-hydroxy-7-(4-hydroxyphenyl)-2,2-dimethyl-2H,6H-benzo[1,2-b:5,4-b']dipyran-6-one}, was obtained by demethylation of the biologically active related compound, 4-O-methylalpinumisoflavone. The molecular structure of the title compound is characterized by a fused tricyclic system that contains an approximately planar benzopyrone ring fragment. The six membered pyran ring adopts a half-chair conformation. Both ring systems show an out-of-plane twist. The dihedral angle between the mean plane of the benzopyrone system and the benzene ring is 54.29 (3)°. The molecules are linked by O-HO hydrogen bonds, forming a molecular tape running along the b axis.

Related literature

For related compounds, see: Kingsford-Adaboh et al. (2001, 2006). For ring puckering analysis, see: Cremer & Pople (1975).

Experimental

Crystal data

C₂₀H₁₆O₅
M_r = 336.34
Monoclinic, P 2₁ /c
a = 13.8333 (3) Å
b = 5.92699 (17) Å
c = 19.8352 (4) Å
= 99.6806 (7)°
V = 1603.13 (7) Å³
Z = 4
Mo K radiation
= 0.10 mm^-1
T = 93 (2) K
0.53 × 0.45 × 0.43 mm

Data collection

Rigaku R-AXIS RAPIDII diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) T_min = 0.771, T_max = 0.958
30574 measured reflections
4676 independent reflections
4296 reflections with I > 2(I)
R_int = 0.036

Refinement

R[F² > 2(F²)] = 0.042
wR(F²) = 0.123
S = 1.04
4676 reflections
237 parameters
H atoms treated by a mixture of independent and constrained refinement
_max = 0.51 e Å^-3
_min = -0.26 e Å^-3

Table 1
Hydrogen-bond geometry (Å, °)

D-HA	D-H	HA	DA	D-HA
O2-H2OO3	0.92 (2)	1.76 (2)	2.6023 (10)	152.2 (17)
O5-H5OO3ⁱ	0.871 (18)	1.943 (18)	2.7823 (10)	161.4 (17)
Symmetry code: (i) $[-x, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: PROCESS-AUTO (Rigaku/MSC, 2004); cell refinement: PROCESS-AUTO ; data reduction: CrystalStructure (Rigaku/MSC, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: CrystalStructure and PLATON (Spek, 2003).

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FB2087 ).

Acknowledgements

This work was supported by the Japanese Society for the Promotion of Science (JSPS) Research Program and RK-A thanks the JSPS for the postdoctoral fellowship awarded.

References

Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan.
Kingsford-Adaboh, R., Ahiano, E., Dittrich, B., Okamoto, H., Kimura, M. & Ishida, H. (2006). Cryst. Res. Technol. 41, 726-733.
Kingsford-Adaboh, R., Osei-Fosu, P., Asomaning, W. A., Weber, M. & Luger, P. (2001). Cryst. Res. Technol. 36, 107-115.
Rigaku/MSC (2004). CrystalStructure and PROCESS-AUTO. Rigaku/MSC, The Woodlands, Texas, USA.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.

organic compounds