Phenyl 2-amino-N,6-O-dibenzyl-2,3-N,O-carbonyl-2-deoxy-1-thio-β-d-glucopyranoside

In the crystal structure of the title compound, C27H27NO5S, the pyranose ring adopts a 4 C 1 chair conformation with puckering parameters Q = 0.639 (2) Å, θ = 174.11 (18) and ϕ = 256 (2)°. The presence of the 2,3-trans-oxazolidinone fixes the conformation of the pyranose ring. The phenyl group attached to the S atom and the benzyl group bonding to the N atom are each disordered over two positions with site occupancies of 0.624 (3):0.376 (3) and 0.526 (3):0.474 (3), respectively. An intermolecular O—H⋯O hydrogen bond is observed.

In the crystal structure of the title compound, C 27 H 27 NO 5 S, the pyranose ring adopts a 4 C 1 chair conformation with puckering parameters Q = 0.639 (2) Å , = 174.11 (18) and ' = 256 (2) . The presence of the 2,3-trans-oxazolidinone fixes the conformation of the pyranose ring. The phenyl group attached to the S atom and the benzyl group bonding to the N atom are each disordered over two positions with site occupancies of 0.624 (3)  manner (Manabe et al., 2006;Satoh et al., 2008). In order to investigate the origin of the high stereosetectivity and its unique character, we are interested in the conformation of the pyranose ring with 2,3-trans-oxazolidinone group.

S2. Experimental
The compound, (I), was prepared as described by Benakli et al. (2001). (I) was dissolved in ethyl acetate at room temperature and hexane was added. The solution was kept at room temperature in a sealed flask for a few days to give single crystals suitable for single-crystal X-ray analysis.

S3. Refinement
The phenyl group bonding to the S atom and the benzyl group bonding to the N atom in (I) were disordered into two parts each other. Occupancy factors of each group were refined, where the atomic displacement parameters of the corresponding atoms in each group were constrained to be the same. Restraints were imposed on the C-C bond distances in the disordered phenyl groups to be 1.39 Å. The positions of H atoms on C atoms were calculated from geometries. The H atom of the hydroxyl group was located in a difference map. All H atoms were treated as riding atoms with C/O-H distances of 1.00, 0.99, 0.95 and 0.84 Å for methyne, methylene, phenyl and hydroxyl, respectively. The U iso (H) values were fixed to be 1.2U eq (C) or 1.5U eq (O). supporting information sup-2 . E64, o1868

Figure 1
A view of the molecular structure of (I), showing the atom labeling scheme. Displacement ellipsoids are drawn at the 50% probability level. The minor parts of the disordered phenyl moieties are omitted for clarity.

Phenyl 2-amino-N,6-O-dibenzyl-2,3-N,O-carbonyl-2-deoxy-1-thio-β-D-glucopyranoside
where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.011 Δρ max = 0.33 e Å −3 Δρ min = −0.34 e Å −3 Absolute structure: Flack (1983), 1983 Friedel pairs Absolute structure parameter: 0.05 (11) Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against all reflections. The weighted R-factor wR and goodness 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 threshold expression of F 2 > 2σ(F 2 ) is used only for calculating R-factors(gt) 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.