(3S*,4S*,E)-tert-Butyl 3,4-dibromo-5-oxo­cyclo­oct-1-ene­carboxyl­ate

Blanco, M.; Garrido, N.M.; Sanz, F.; Diez, D.

doi:10.1107/S1600536811053852

Volume 68
Part 1
Page o232
January 2012

Received 13 December 2011
Accepted 14 December 2011
Online 23 December 2011

Key indicators
Single-crystal X-ray study
T = 298 K
Mean (C-C) = 0.006 Å
R = 0.029
wR = 0.075
Data-to-parameter ratio = 13.1
Details

(3S,4S,E)-tert-Butyl 3,4-dibromo-5-oxocyclooct-1-enecarboxylate

Magda Blanco,^a Narciso M. Garrido,^a ^* Francisca Sanz ^b and David Diez ^a

^aDepartamento de Quimica Organica, Universidad de Salamanca, Plaza de los Caidos, 37008 Salamanca, Spain, and ^bServicio General de Rayos X, Universidad de Salamanca, Plaza de los Caidos, 37008 Salamanca, Spain
Correspondence e-mail: nmg@usal.es

The title compound, C₁₃H₁₈Br₂O₃, was prepared by a bromination reaction of (1E,3Z)-methyl 5-oxocycloocta-1,3-dienecarboxylate, which was obtained by an epoxydation reaction of tert-butyl cyclooct-1,3-dienecarboxylate. The crystal structure confirms unequivocally the absolute configuration of both chiral centres to be S. In the crystal, C-HO interactions link the molecules into chains running along the c axis.

Related literature

For the Michael addition of enantiomerically pure lithium amides, see: Davies et al. (2005). For their importance in pharmacology, see: Fülöp et al. (2001). For the reactivity of the cycloocta-1,5-diene in basic medium, see: Huber et al. (1969, 1970). For the preparation of analogous unsaturated cyclooctane esters, see: Garrido et al. (2008).

Experimental

Crystal data

C₁₃H₁₈Br₂O₃
M_r = 382.09
Orthorhombic, P c a 2₁
a = 14.0658 (4) Å
b = 9.5990 (3) Å
c = 11.2657 (3) Å
V = 1521.07 (8) Å³
Z = 4
Cu K radiation
= 6.76 mm^-1
T = 298 K
0.24 × 0.14 × 0.10 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2006) T_min = 0.370, T_max = 0.509
10215 measured reflections
2170 independent reflections
2153 reflections with I > 2(I)
R_int = 0.048

Refinement

R[F² > 2(F²)] = 0.029
wR(F²) = 0.075
S = 1.09
2170 reflections
166 parameters
1 restraint
H-atom parameters constrained
_max = 0.32 e Å^-3
_min = -0.46 e Å^-3
Absolute structure: Flack (1983), 803 Friedel pairs
Flack parameter: 0.06 (3)

Table 1
Hydrogen-bond geometry (Å, °)

D-HA	D-H	HA	DA	D-HA
C3-H3O3ⁱ	0.98	2.57	3.525 (5)	165
C8-H8AO3ⁱ	0.97	2.63	3.590 (6)	172
Symmetry code: (i) $[-x+2, -y+2, z-{\script{1\over 2}}]$ .

Data collection: APEX2 (Bruker 2006); cell refinement: SAINT (Bruker 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BT5753 ).

Acknowledgements

The authors are grateful to the FSE, the Spanish MICINN (EUI 2008-00173) and (CTQ 2009-11172/BQU) and the Junta de Castilla y Leon (Spain) for financial support (GR-178 and SA001A09). The authors also thank Grupo Santander for the doctoral fellowship awarded to MB.

References

Bruker (2006). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
Davies, S. G., Smith, A. D. & Price, P. D. (2005). Tetrahedron Asymmetry, 16, 2833-2891.
Flack, H. D. (1983). Acta Cryst. A39, 876-881.
Fülöp, F. (2001). Chem. Rev. 101, 2181-2204.
Garrido, N. M., Blanco, M., Cascón, I. F., Díez, D. & Vicente, V. M. (2008). Tetrahedron Asymmetry, 19, 2895-2900.
Huber, A. J. & Reimlinger, H. (1969). Synthesis, pp. 97-112.
Huber, A. J. & Reimlinger, H. (1970). Synthesis, pp. 405-430.
Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453-457.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.

organic compounds

(3S*,4S*,E)-tert-Butyl 3,4-dibromo-5-oxocyclooct-1-enecarboxylate