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Volume 69 
Part 1 
Page o99  
January 2013  

Received 14 November 2012
Accepted 12 December 2012
Online 15 December 2012

Key indicators
Single-crystal X-ray study
T = 296 K
Mean [sigma](C-C) = 0.002 Å
R = 0.044
wR = 0.118
Data-to-parameter ratio = 19.1
Details
Open access

rac-Ethyl 2-hydroxy-2,7,7-trimethyl-4-(4-nitrophenyl)-5-oxo-3,4,5,6,7,8-hexahydro-2H-chromene-3-carboxylate

aBaku State University, Baku, Z. Khalilov St 23, AZ-1148, Azerbaijan, and bVladimir State University, 600000 Vladimir, Gor'ky St 87, Russia
Correspondence e-mail: orglab@mail.ru

The title molecule, C21H25NO7, has four stereogenic centres and crystallized as a racemate. It consists of enantiomeric pairs with the relative configuration rac-(1R*,2S*,3R*). The cyclohexenone ring adopts an envelope conformation; the dimethyl-substituted C atom lies 0.640 (1) Å out of the mean plane formed by the rest of the ring atoms (r.m.s. deviation = 0.016 Å). The oxacyclohexene ring adopts a half-chair conformation, the hydroxy- and carboxyl-substituted C atoms lying -0.336 (1) and 0.419 (1) Å, respectively, out of the mean plane formed by the rest of the ring atoms (r.m.s. deviation = 0.002 Å). In the crystal, O-H...O hydrogen bonds link the molecules into a chain along the c-axis direction.

Related literature

For general background to 2H-chromenes and their derivatives, see: Cai (2008[Cai, S. X. (2008). Bioorg. Med. Chem. Lett. 18, 603-607.]); Valenti et al. (1993[Valenti, P., Da Re, P., Rampa, A., Montanari, P., Carrara, M. & Cima, L. (1993). Anticancer Drug. Des. 8, 349-360.]); Hyana & Saimoto (1987[Hyana, T. & Saimoto, H. (1987). Jpn Patent JP 621 812 768.]); Tang et al. (2007[Tang, Q.-G., Wu, W.-Y., He, W., Sun, H.-S. & Guo, C. (2007). Acta Cryst. E63, o1437-o1438.]). For their anticancer activity, see: Afantitis et al. (2006[Afantitis, A., Melagraki, G., Sarimveis, H., Koutentis, P. A., Markopoulosd, J. & Igglessi-Markopoulou, O. (2006). Bioorg. Med. Chem. 14, 6686-6694.]); Cai (2007[Cai, S. X. (2007). Recent Patents Anticancer Drug Discov. 2, 79-101.]). For puckering parameters, see: Cremer & Pople (1975[Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.]).

[Scheme 1]

Experimental

Crystal data
  • C21H25NO7

  • Mr = 403.42

  • Monoclinic, P 21 /c

  • a = 10.4163 (8) Å

  • b = 24.2608 (18) Å

  • c = 8.0796 (6) Å

  • [beta] = 96.437 (2)°

  • V = 2028.9 (3) Å3

  • Z = 4

  • Mo K[alpha] radiation

  • [mu] = 0.10 mm-1

  • T = 296 K

  • 0.30 × 0.20 × 0.20 mm

Data collection
  • Bruker APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1998[Sheldrick, G. M. (1998). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.971, Tmax = 0.980

  • 23423 measured reflections

  • 5078 independent reflections

  • 4084 reflections with I > 2[sigma](I)

  • Rint = 0.022

Refinement
  • R[F2 > 2[sigma](F2)] = 0.044

  • wR(F2) = 0.118

  • S = 1.00

  • 5078 reflections

  • 266 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • [Delta][rho]max = 0.30 e Å-3

  • [Delta][rho]min = -0.20 e Å-3

Table 1
Hydrogen-bond geometry (Å, °)

D-H...A D-H H...A D...A D-H...A
O2-H2...O3i 0.82 (2) 2.08 (2) 2.8881 (15) 172 (2)
Symmetry code: (i) [x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2005[Bruker (2005). SAINT-Plus and APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT-Plus (Bruker, 2005[Bruker (2005). SAINT-Plus and APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: AA2078 ).


Acknowledgements

We thank Baku State University and Vladimir State University for supporting this study.

References

Afantitis, A., Melagraki, G., Sarimveis, H., Koutentis, P. A., Markopoulosd, J. & Igglessi-Markopoulou, O. (2006). Bioorg. Med. Chem. 14, 6686-6694.  [CrossRef] [PubMed] [ChemPort]
Bruker (2005). SAINT-Plus and APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.
Cai, S. X. (2007). Recent Patents Anticancer Drug Discov. 2, 79-101.
Cai, S. X. (2008). Bioorg. Med. Chem. Lett. 18, 603-607.  [PubMed]
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.  [CrossRef] [ChemPort] [ISI]
Hyana, T. & Saimoto, H. (1987). Jpn Patent JP 621 812 768.
Sheldrick, G. M. (1998). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]
Tang, Q.-G., Wu, W.-Y., He, W., Sun, H.-S. & Guo, C. (2007). Acta Cryst. E63, o1437-o1438.  [CSD] [CrossRef] [details]
Valenti, P., Da Re, P., Rampa, A., Montanari, P., Carrara, M. & Cima, L. (1993). Anticancer Drug. Des. 8, 349-360.  [ChemPort] [PubMed]


Acta Cryst (2013). E69, o99  [ doi:10.1107/S1600536812050581 ]

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