Crystal structure of racemic [(1R,2S,3R,4S,6S)-2,6-bis(furan-2-yl)-4-hydroxy-4-(thiophen-2-yl)cyclohexane-1,3-diyl]bis(thiophen-2-ylmethanone)

The central cyclohexane ring has a chair conformation. In the crystal, molecules are linked by C—H⋯O hydrogen bonds and C—H⋯π interactions, forming layers parallel to (100).

In the title compound, C 28 H 22 O 5 S 3 , the central cyclohexane ring adopts a chair conformation. The atoms of the furan ring attached to the 6-position of the central cyclohexane ring are disordered over two sets of sites with occupancies of 0.832 (5) and 0.168 (5). The hydroxy group is disordered over two positions (at the 4-and 6-positions of the cyclohexane ring) in the ratio 0.832 (5):0.168 (5). In the crystal, molecules are linked by C-HÁ Á ÁO hydrogen bonds and C-HÁ Á Á interactions, forming layers parallel to (100).

Structural commentary
In the title compound, Fig. 1, the central cyclohexane ring adopts a chair conformation [the puckering parameters are Q T View of the title compound with the atom-numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 30% probability level. The minor disorder component is not shown, for clarity.

Figure 2
View of the packing of the title compound down the a axis. For clarity, the minor disorder component is not shown. Table 1 Hydrogen-bond geometry (Å , ).
(Complete Neglect of Differential Overlap) method (Pople & Beveridge, 1970), the spatial view of the single molecule, with atomic labels, calculated as a closed-shell in a vacuum is shown in Fig. 4. The net charges on atoms O1, O2, O3, O4, O5, S1, S2 and S3 are À0.330, À0.113, À0.279, À0.341, À0.158, À0.014, À0.055 and À0.021 e À , respectively. This is useful as prediction of the electron-rich and electron-poor sites of a molecule provides a rough estimate of chemical and physical properties of the molecule. The dipole moment of the title molecule is 3.626 Debye. The HOMO and LUMO energy levels are À10.31 and 1.72 eV, respectively. The values of the HOMO and LUMO energy levels determine the way in which the molecule interacts with other species and help to characterize the chemical reactivity and kinetics of the molecule. The geometrical parameter values obtained by the X-ray structure determination of the title compound are consistent with those calculated by the CNDO/2 method within the error limits (Table 2). Small differences between the theoretical and experimental results may result from the calculations assuming the molecule is in a vacuum.

Figure 4
Spatial view of the molecule of the title compound calculated using the CNDO method.

Figure 3
View of the packing of the title compound down the b-axis. For clarity, the minor disorder component is not shown.

[(1R,2S,3R,4S,6S)-2,6-Bis(furan-2-yl)-4-hydroxy-4-(thiophen-2-yl)cyclohexane-1,3-diyl]bis(thiophen-2ylmethanone)
Crystal data Special details Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles Refinement. Refinement on F 2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The observed criterion of F 2 > 2sigma(F 2 ) is used only for calculating -R-factor-obs etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.