6-Acetoxymethyl-3-[(2-hydroxy-3-methoxybenzylidene)amino]-3,4,5,6-tetrahydro-2H-pyran-2,4,5-triyl triacetate

The title compound, C22H27NO11, was synthesized by the reaction of 4,5-diacetoxy-6-acetoxymethyl-3-aminotetrahydropyran-2-yl acetate and 2-hydroxy-3-methoxybenzaldehyde in ethanol. The molecule contains two six-membered rings, one of which is in a chair conformation, and an intramolecular O—H⋯N hydrogen bond is present.


D-HÁ
The other dihedral angle between the four acetic acid groups and the plane of C9, C10, C12, C13 are in the range of 57.0-111.7°. There is an intramolecular O-H···N hygrogen bond between the phenol and imido-group (Table 1). The distance of N1···H1 is substantially shorter than the van der Waals distance of 2.75 Å for the N and H distance. The hydrogen bond between the phenol and imido-group are similar to those found in the crystal structure of 5,5'-Dimethoxy-2,2'-[4,5-dimethyl-o-phenylenebis(nitrilomethylidyne)]diphenol (Kargar, et al. 2010). In the molecule, the C9 has S* configuration, while the C10, C11, C12, C13 are in R* configuration which form a R* configuration molecule.

Refinement
All H atoms were positioned geometrically and were refined as riding, with (C-H 0.93-0.98 Å, O-H 0.82 Å with U iso (H) = 1.2 U eq (aromatic C) and U iso (H) = 1.5U eq (other C or O).

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )