The crystal structure of the title compound, C28H38O11, solved and refined against synchrotron diffraction data, contains two formula units in the asymmetric unit. In both molecules, the dihydropyran ring along with its methyl substituents is disordered and adopts two alternative half-chair conformations. The occupancy of the major conformers of the two molecules refined to 0.858 (5) and 0.523 (5).
The title compound, C13H24O10·4H2O, is the methyl glycoside of a disaccharide structural element present in the backbone of the capsular polysaccharide from Klebsiella K1, which contains only three sugars and a substituent in the polysaccharide repeating unit. The conformation of the title disaccharide is described by the glycosidic torsion angles ϕH = 51.1 (1)° and ψH = 25.8 (1)°. In the crystal, a number of O—H⋯O hydrogen bonds link the methyl glycoside and water molecules, forming a three-dimensional network. One water molecule is disordered over two positions with occupancies of 0.748 (4) and 0.252 (4).
In the crystal structure of the title compound, C27H27NO5S, the pyranose ring adopts a 4
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.
The title compound, C22H22N2O10, was prepared by the glycosidation method through nitrite displacement on substituted nitrophthalonitrile. The molecule contains a benzene ring, two nitrile groups and an acetyl-protected d-glucose fragment which adopts a chair conformation. The absolute configuration was determined by the use of d-glucose as starting material. All substituents of the protected sugar are in equatorial positions, with the exclusive presence of the α-anomer. The crystal packing is stabilized by C—H⋯O and C—H⋯N hydrogen-bonding interactions.
In the crystal structure of the title compound, C24H27NO11, a substituted tetraacetyl glucopyranoside derivative, weak intermolecular C—H⋯O hydrogen bonds link the molecules into ribbons propagated in . The d configuration has been attributed on the basis of the synthesis and the β anomer has been determined from the structure.
In the title compound, C23H23NO6S, the plane of the N-phthalimido group makes a dihedral angle of 67.4 (1)° with the least square plane of the sugar ring defined by the C2, C3, C5 and O5 atoms using standard glucose nomenclature. The thioethyl group has the exo-anomeric conformation. In the crystal, intermolecular hydrogen bonds involving the hydroxy groups and the carbonyl O atoms of adjacent N-phthalimido groups form chains parallel to the b axis. The chains are further stabilized by C—H⋯π interactions.
The enantiomerically pure title compound, C23H30O12, crystallizes in the chiral space group P212121. The O-acetylated-glucopyranoside moiety adopts a chair conformation. Numerous C—H⋯O interactions as well as a C—H⋯π interaction are present in the crystal structure.
In the title compound, C14H25NO11·2H2O, the primary hydroxyl group connected to the anomeric C atom of the N-acetyl-β-d-glucopyranose residue exhibits positional disorder, with occupancy factors for the α and β anomers of 0.77 and 0.23, respectively. The two torsion angles (Φ and Ψ) and the bridge angle (τ) that describe conformation of the glycosidic linkage between the galactopyranose and glucopyranose rings are Φ = −81.6 (3)°, Ψ = 118.1 (2)° and τ = 115.2 (2)°. Two water molecules stabilize the molecular packing by forming hydrogen bonds with the saccharide residues.
Molecules of the title compound, C24H28O12, are linked by intermolecular C—H⋯O hydrogen bonds. Bond lengths and angles are normal.
The title compound, C13H24O11·4H2O, forms extended hydrogen-bonded networks. These are present between disaccharides, but not as inter-residue hydrogen bonds, as well as to water molecules that in addition form an intermolecular chain of hydrogen bonds. The conformation of the disaccharide is described by the glycosidic torsion angles ϕH = −34° and ψH = −5°. Macroscopically, the disaccharide was observed to be hygroscopic.
In the title compound, C30H31NO6S, the plane of the N-phthalimido group is nearly orthogonal to the least-squares plane of the sugar ring (defined by atoms C2, C3, C5 and O5 using standard glucose nomenclature), making a dihedral angle of 72.8 (1)°. The thioethyl group has the exo-anomeric conformation. The hydroxy group forms an intermolecular hydrogen bond to the O atom in the sugar ring, generating  chains. There are four close π–π contacts with centroid–centroid distances less than 4.0 Å, all with dihedral angles between the interacting π systems of only ≃ 8°, supporting energetically favourable stacking interactions.
The title molecule, C30H28O6, possesses crystallographically imposed twofold symmetry, with two central C atoms in the naphthalene unit lying on the rotation axis along . The 4-ethoxybenzoyl groups at the peri positions of the naphthalene ring system are disordered over two sets of sites with occupancies of 0.769 (4) and 0.231 (4). They are directed in opposite directions from the naphthalene plane (anti orientation). For the major component, the dihedral angle between the aroyl benzene ring and the naphthalene ring system is 75.62 (13)° [minor component 75.5 (4)°], and that between the aroyl benzene rings is 32.58 (15)°. In the crystal, molecules are linked via C—H⋯O and C—H⋯π interactions, forming a three-dimensional network.
The crystalline form of 1-deoxy-l-mannitol, C6H14O5, exists as an extensively hydrogen-bonded structure with each molecule acting as a donor and acceptor for five hydrogen bonds. There are no unusual crystal-packing features; the absolute configuration was determined from the use of 6-deoxy-l-mannose (l-rhamnose) as the starting material.
The title compound, C7H10F6O4, was isolated as an unexpected product from a reaction of tantalum(V) methoxide with hexafluoroacetylacetone in a methanol solution. The asymmetric unit consists of one half-molecule with the middle C atom lying on a twofold axis. The crystal structure is stabilized by O—H⋯O and an array of C—H⋯F hydrogen-bonding interactions. These interactions link the molecules into a stable supramolecular three-dimensional network. The molecules pack in a ribbon-like form in the ac plane as a result of these interactions.
The crystal structure unequivocally confirms the relative stereochemistry of the title compound, C6H13FO5 [6-deoxy-6-fluoro-d-galactitol or (2S,3R,4R,5S)-6-fluorohexane-1,2,3,4,5-pentaol]. The absolute stereochemistry was determined from the use of d-galactose as the starting material. In the crystal, the molecules are linked by O—H⋯O and O—H⋯F hydrogen bonds, forming a three-dimensional network with each molecule acting as a donor and acceptor for five hydrogen bonds.
In the title molecule, C26H25FN2O5, the fluoromethoxy-, methoxy- and trimethoxy-substituted benzene rings form dihedral angles of 12.65 (2), 84.15 (2) and 55.67 (2)°, respectively, with the imidazole ring. The crystal structure is stabilized weak intermolecular C—H⋯F and C—H⋯O hydrogen bonds.
In the title compound, C22H18F2O3, the two fluoro-substituted rings form dihedral angles of 25.89 (15) and 55.00 (12)° with the central benzene ring. The ethoxy group in the molecule is disordered over two positions with a site-occupancy ratio of 0.662 (7):0.338 (7). In the crystal, molecules are linked by C—H⋯O hydrogen bonds into chains along the a axis. The crystal packing is further stabilized by C—H⋯π and π—π interactions, with centroid–centroid distances of 3.8605 (15) Å.
The asymmetric unit of the title compound, C36H30O4, contains two crystallographically independent molecules of similar geometry. In both molecules, the methoxymethoxy groups are disordered over two positions with refined site occupancies of 0.613 (3):0.387 (3) and 0.589 (4):0.411 (4). The dihedral angles between the naphthalene planes within the same molecule are 71.72 (7) and 71.73 (8)°. In the crystal, neighbouring molecules are linked by intermolecular C—H⋯O hydrogen bonds, forming double chains parallel to the c axis.
The title compound, C22H26O9, crystallizes with two independent molecules in the asymmetric unit in which the dihedral angles between the two benzene rings are 21.4 (2) and 5.1 (2)°. An intramolecular O—H⋯O hydrogen bond occurs in each molecule. Intermolecular C—H⋯O hydrogen bonds stabilize the crystal structure.
The pyranoside ring in the title compound, C21H24O11, has a chair conformation with the substituted benzene ring occupying an equatorial position. The crystal packing is dominated by C—H⋯O interactions that lead to the formation of supramolecular layers in the ab plane.
In the title compound, C28H24F2N2O6S, the whole molecule is disordered over two sites with refined occupancies of 0.778 (3) and 0.222 (3). The central benzene ring makes dihedral angles of 56.0 (4), 34.5 (4) and 70.9 (4)°, respectively, with the two terminal benzene rings and the 1,3,4-oxadiazole ring in the major component of the disordered molecule. The corresponding angles in the minor component are 59.7 (16), 25.6 (13) and 75.5 (14)°. In the crystal, molecules are linked via C—H⋯F, C—H⋯N, C—H⋯O and C—H⋯S hydrogen bonds into a three-dimensional network. In addition, C—H⋯π interactions are observed.
In the title compound, C25H21BrN2O3·H2O, the benzimidazole fragment and the water molecule of crystallization are each disordered over two sets of sites of equal occupancy. The dihedral angles between the least-squares planes of the benzimidazole and the 3-ethoxy- and 4-bromobenzene rings are 86.9 (6) and 85.1 (1)°, respectively in one disorder component. The crystal packing is stabilized by intermolecular O—H⋯O, O—H⋯N and N—H⋯N hydrogen bonds, which link the molecules into chains along the a axis.
The title compound, C22H25F5N4O9, is a stable pentafluorophenyl ester intermediate in the synthesis of novel homo-oligomeric structures containing branched carbon chains. The structure is epimeric to the previously characterized dimeric pentafluorophenyl ester with stereochemistry (3R,4R,5R), which was synthesized using d-ribose as starting material. The crystal structure of the title molecule removes any ambiguities arising from the relative stereochemistries of the six chiral centres. Two hydrogen bonds, bifurcating from the NH group, stabilize the crystal: one intramolecular and one intermolecular, both involving O atoms of the methoxy groups. The asymmetric unit contains two independent molecules not related by any pseudo-symmetry operators. The major conformational differences are localized, leading to one molecule being extended compared to the other. The collected crystal was twinned (twin ratio is 0.939:0.061), and the azide group is positionally disordered over two positions in one molecule [occupancy ratio 0.511 (18):0.489 (18)].
4-Deoxy-4-fluoro-β-d-glucopyranose, C6H11FO5, (I), crystallizes from water at room temperature in a slightly distorted 4
1 chair conformation. The observed chair distortion differs from that observed in β-d-glucopyranose [Kouwijzer, van Eijck, Kooijman & Kroon (1995 ▶). Acta Cryst. B51, 209–220], (II), with the former skewed toward a B
C3,O5 (boat) conformer and the latter toward an O5
C2 (twist–boat) conformer, based on Cremer–Pople analysis. The exocyclic hydroxymethyl group conformations in (I) and (II) are similar; in both cases, the O—C—C—O torsion angle is ∼−60° (gg conformer). Intermolecular hydrogen bonding in the crystal structures of (I) and (II) is conserved in that identical patterns of donors and acceptors are observed for the exocyclic substituents and the ring O atom of each monosaccharide. Inspection of the crystal packing structures of (I) and (II) reveals an essentially identical packing configuration.
Although 6-azido-6-deoxy-l-galactose in aqueous solution is in equilibrium between the open-chain, furanose and pyranose forms, it crystallizes solely as 6-azido-6-deoxy-α-l-galactopyranose monohydrate, C6H11N3O5·H2O, with the six-membered ring adopting a chair conformation. The structure exists as hydrogen-bonded chains, with each molecule acting as a donor and acceptor of five hydrogen bonds. There are no unusual crystal packing features and the absolute configuration was determined from the use of 1-azido-1-deoxy-d-galactitol as the starting material.