[1R-(1α,2α,4α,5β,6α,7α)]-4-Benzoyl­oxymethyl-5,6-dihy­droxy-3,8-dioxa­tricyclo­[5.1.0.02,4]octan-5-yl acetate (3-deacetyl­crotepoxide) from Kaempferia rotunda Val.

Sirat, H.M.; Feng, Y.S.; Awang, K.; Ng, S.W.

doi:10.1107/S1600536810042686

Volume 66
Part 11
Page o2945
November 2010

Received 20 October 2010
Accepted 20 October 2010
Online 30 October 2010

Key indicators
Single-crystal X-ray study
T = 100 K
Mean (C-C) = 0.004 Å
R = 0.038
wR = 0.117
Data-to-parameter ratio = 9.4
Details

[1R-(1,2,4,5,6,7)]-4-Benzoyloxymethyl-5,6-dihydroxy-3,8-dioxatricyclo[5.1.0.0^2,4]octan-5-yl acetate (3-deacetylcrotepoxide) from Kaempferia rotunda Val.

Hasnah Mohd Sirat,^a Yau Sui Feng,^a Khalijah Awang ^b and Seik Weng Ng ^b ^*

^aDepartment of Chemistry, Universiti Teknologi Malaysia, 81310 Skudai, Malaysia, and ^bDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
Correspondence e-mail: seikweng@um.edu.my

The title compound, C₁₆H₁₆O₇, isolated from Kaempferia rotunda rhizomes, features a six-membered cyclohexane ring that adopts a twisted-boat conformation owing to the presence of two adjacent epoxide attachments that lock in four of the six axial positions. The CH₃CO₂- and HO- substituents occupy equatorial positions. However, the bond angles at the ring carbon connected to the C₆H₅CO₂CH₂- substituent deviate signifcantly from the idealized tetrahedral angles as the carbon atom is part of an epoxide ring. In the crystal, the molecules are linked into chains by O-HO hydrogen bonds.

Related literature

For the isolation of the compound from Kaempferia rotunda, see: Pancharoen et al. (1996).

Experimental

Crystal data

C₁₆H₁₆O₇
M_r = 320.29
Orthorhombic, P 2₁ 2₁ 2₁
a = 5.7451 (7) Å
b = 7.1746 (9) Å
c = 35.708 (5) Å
V = 1471.9 (3) Å³
Z = 4
Mo K radiation
= 0.12 mm^-1
T = 100 K
0.35 × 0.05 × 0.05 mm

Data collection

Bruker SMART APEX diffractometer
14228 measured reflections
2011 independent reflections
1730 reflections with I > 2(I)
R_int = 0.073

Refinement

R[F² > 2(F²)] = 0.038
wR(F²) = 0.117
S = 1.12
2011 reflections
213 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
_max = 0.37 e Å^-3
_min = -0.33 e Å^-3

Table 1
Hydrogen-bond geometry (Å, °)

D-HA	D-H	HA	DA	D-HA
O5-H5O4ⁱ	0.84 (3)	2.05 (3)	2.887 (3)	172 (4)
Symmetry code: (i) $[-x+1, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BT5386 ).

Acknowledgements

We thank the University of Malaya for supporting this study.

References

Barbour, L. J. (2001). J. Supramol. Chem. 1, 189-191.
Bruker (2009). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Pancharoen, O., Tuntiwachwuttikul, P. & Taylor, W. C. (1996). Phytochemistry, 43, 305-308.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.

organic compounds

[1R-(1,2,4,5,6,7)]-4-Benzoyloxymethyl-5,6-dihydroxy-3,8-dioxatricyclo[5.1.0.02,4]octan-5-yl acetate (3-deacetylcrotepoxide) from Kaempferia rotunda Val.