Bis{(R)-N-[(R)-2-benzyloxy-1-(4-tert-butylphenyl)ethyl]-2-methylpropane-2-sulfinamide} monohydrate

The asymmetric unit of the title compound, 2C23H33NO2S·H2O, contains one organic molecule in a general position and one co-crystallized water molecule on a crystallographic twofold axis. Each water molecule serves as a hydrogen-bond donor to a pair of S=O acceptors on symmetry-related molecules. Thus, each trio of molecules forms one title formula unit. These groupings are further connected along [010] via weak non-classical C—H⋯O hydrogen bonds.

The asymmetric unit of the title compound, 2C 23 H 33 NO 2 SÁ-H 2 O, contains one organic molecule in a general position and one co-crystallized water molecule on a crystallographic twofold axis. Each water molecule serves as a hydrogen-bond donor to a pair of S O acceptors on symmetry-related molecules. Thus, each trio of molecules forms one title formula unit. These groupings are further connected along [010] via weak non-classical C-HÁ Á ÁO hydrogen bonds.

Comment
We report the synthesis, isolation, and characterization of the protected 1,2-aminoalcohol (R)-N-((R)-2-(benzyloxy)-1-(4-(tert-butyl)phenyl)ethyl)-2-methylpropane-2-sulfinamide ( Fig. 1) from the addition of 4-tert-butylphenylmagnesium bromide to an N-tert-butanesulfinyl imine ( Fig. 2) according to the procedure of Ellman (Tang et al., 2001). 1,2-Aminoalcohols are found in a variety of pharmaceutically active compounds and are an important component of the chiral pool (Bergmeier, 2000). The method of Ellman and Tang is one of the most direct to monosubstituted aminoalcohols and relies upon the chiral ammonia equivalent, 2-methyl-2-propanesulfinamide (tert-butanesulfinamide). In the original report, the absolute configuration of the products was determined by comparison of optical rotations and no structures of the products of these reactions have been reported in the database. This structure is consistent with the sense of induction reported by Ellman and Tang (Tang et al., 2001). There are 21 structures of N-sulfinyl-protected 1,2-aminoalcohols in the Cambridge Stuctural Database, but only two of these structures have no substitution at the 1 position and have substitution at the 2 position (Allen, 2002, refcodes FOKDUF, YEQBOM). Neither of these two structures was made by the method we used and neither has an aryl group at the 2 position.

Experimental
Dry solvents were prepared from ACS grade, inhibitor free solvents by passage through activated molecular sieves in an Innovative Technology solvent purification system. CDCl 3 was purchased from Cambridge Isotope Laboratories, Inc., dried over molecular sieves, and stored in a desiccator until use. 1 H and 13 C NMR spectra were recorded on an Avance 500 MHz s pectrometer with residual protiated solvent as a reference.

Refinement
All H atoms were located from difference Fourier maps and freely refined.

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. All hydrogen atoms were found from the difference Fourier map and refined freely. The absolute configuration was deterimined using 3436 quotients, which gave a Flack parameter of -0.01 (3) (Parsons andFlack, 2004, Parson et al., 2013). This is essentially the same value obtained without D obs (h) as a restraint, which resulted in a Flack parameter of -0.01 (4), calculated from 5617 Friedel pairs (Flack, 1983).