title: The crystal structure of isobutyl 2,3,4-tri-O-acetyl-1-thio-beta-D-xylopyranoside.
abstract: Isobutyl 2,3,4-tri-O-acetyl-1-thio-beta-D-xylopyranoside is monoclinic, P21, with a = 10.134(4), b = 7.748(3), c = 11.726(4) A, beta = 96.63(3) degrees, V = 914.55 A3, Z = 2, Dm = 1.262, Dx = 1.264 g . cm-3, mu(MoK alpha) = 226 M-1. The X-ray intensities of 1724 reflections were measured with Nb-filtered MoK alpha radiation (lambda = 0.7107 A) at room temperature. The structure was solved by direct methods, and refined by full-matrix least squares, with anisotropic thermal parameters for the carbon and oxygen atoms and isotropic thermal parameters for the hydrogen atoms, to a final agreement factor of R = 0.08. The molecule has the 4C1(D) conformation, with puckering parameters Q = 0.582 A, theta = 5.6 degrees, phi = 334.7 degrees. The acetyl groups have the planar, (S)-cis configuration most commonly observed. They are oriented, as in many other per-O-acetylated aldopyranosides, with the acetyl planes within +/- 30 degrees of the C-H bond at the ring-carbon atom to which they are attached. Although this is primarily a van der Waals structure, there is some evidence for CH---O hydrogen-bonding.
mesh_terms: D002236:Carbohydrate Conformation; D008958:Models, Molecular; D013863:Thioglucosides; D013865:Thioglycosides; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D013863:Thioglucosides; D013865:Thioglycosides; C048070:isobutyl 2,3,4-tri-O-acetyl-1-thio-beta-xylopyranoside