The asymmetric unit of the title compound, 2C20H22N3O3 +·SO4 2−·H2O, contains four cations, two sulfate anions and two lattice water mol­ecules. One of the four cations shows a different conformation of the hy­droxy­ethyl group; the remaining three are all essentially superimposable. Two cations exhibit two-site orientational disorder [ratios = 0.524 (5):0.476 (5) and 0.616 (6):0.384 (6)] of the last two atoms of their hy­droxy­ethyl groups, and one water mol­ecule is disordered over two positions in a 0.634 (13):0.366 (13) ratio. Each imine H atom is intra­molecularly in contact with the adjacent carboxyl O atom, forming an S(6) motif, while all the carb­oxy­lic acid H atoms are hydrogen bonded to O atoms of the sulfate anions. Other notable hydrogen-bond inter­actions involve (methyl­ene, phenyl and imine chain) C—H⋯O (sulfate and carbox­yl) and O—H⋯O(water) contacts, making up a comprehensive three-dimensional network involving D 2 2(n), with n = 4–6 and 15–16, and C 2 2(17) classical hydrogen-bond motifs. The crystal investigated was twinned by pseudomerohedry with a twin component ratio of 0.4745 (12):0.5255 (12).

The title compound, C10H10O4, crystallizes with the well-known carb­oxy­lic acid dimer-forming R 2 2(8) hydrogen-bond motif. Chains approximately parallel to (-1-12) are then built through C(methyl­ene,phen­yl)–H⋯O(carbon­yl) inter­actions [C(6) and C(8) motifs] with one (meth­yl)C—H⋯π inter­action providing inter­planar binding. The weakness of the latter inter­action is consistent with the difficulty experienced in obtaining suitable single crystals.

In the title compound, C45H40N4O5, the cyclo­hexane entity on the (3-cyano-2,5-dihydro­furan-2-yl­idene)propane­dinitrile group, which replaces the usual dimethyl substituents, has not perturbed the delocalization geometry significantly. Weak inter­molecular inter­actions, viz. C—H⋯N(cyano), C—H⋯O(ether), C—H⋯π and π–π [between the aromatic rings with the shortest centroid–centroid distance of 3.603 (3) Å], consolidate the crystal packing, which exhibits voids of 57 Å3.

In the title compound, C22H22N4O2·0.25C3H6O, the disordered acetone mol­ecule lies with partial occupancy about the 2 axis. The mol­ecule of the malononitrile derivative is essentially planar excluding the methyl groups, with the largest deviation from the mean plane through the non-H atoms being 0.1955 (13) Å. Two rotamers with different orientations of the benzene ring are observed in the ratio of 0.919 (2):0.081 (2), and as a result the OH group is disordered over two sets of sites. In the crystal, the mol­ecules form ribbons along (101) utilizing a strong O—H⋯N(cyano) hydrogen bond. Inter­leaving of the nearly planar ribbons is provided by the twofold disordered acetone molecule through C—H⋯O inter­actions.

The title compound, C6H11NO3S, crystallizes utilizing a three-dimensional set of O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds. The 1,3-oxazolidin-2-one ring adopts an envelope conformation with the C atom bearing the hy­droxy­methyl group as the flap.

The title compound [systematic name: tetra­benzyl (1R,2R,3S,4R,5R,6S)-4-(tert-butyl­diphenyl­sil­yloxy)-3,5,6-tris­(meth­oxy­meth­oxy)cyclo­hexane-1,2-diyl bis­phosphate], C56H68O15P2Si, was isolated as an inter­mediate in the preparation of a phosphatidylinositol phosphate for biological studies. In the crystal, the mol­ecules are connected via one methyl­ene C—H⋯π and two weak phen­yl–ether C—H⋯O inter­actions. One benz­yloxy group is disordered over two overlapping positions with an occupancy ratio of 0.649 (7):0.351 (7).

The title compound, C29H35NO6.0.334C3H8O, a novel chiral N-(fluoren-9-yl­methyl­oxyxcarbon­yl) precursor, crystallizes with two independent carbamate (M) mol­ecules and propan-2-ol solvent mol­ecules in the unit cell. Its crystal structure has been determined from barely adequate data obtained from a multi-fragment needle crystal. In the crystal, N—H⋯O hydrogen bonds link M mol­ecules related by translation along the a axis into two independent chains. The ordered solvent mol­ecule, having a partial occupancy of 0.334, is attached to one independent M mol­ecule through O—H⋯O hydrogen bonds. The crystal packing exhibits weak inter­molecular C—H⋯O inter­actions and voids of 270 Å3 filled with randomly disordered solvent mol­ecules which were handled using the SQUEEZE methodology.

The title mol­ecule, C35H25N3O3, packs utilizing C—H⋯π attractive inter­actions causing the identical 4-benzyl­oxyphenyl groups to pack with different conformational angles. This difference is consistent with the variable inter­planar dihedral angles found in closely related structures.

The title compound, C29H28N4O2, excluding the hydroxyethyl and methyl groups, is slightly twisted from planarity so that the terminating indol-2-yl­idene and furan-2-yl­idene moiety planes subtend a dihedral angle of 6.27 (8)°. A small inwards fold in the polymethine atom chain is consistent with centrosymmetric dimer formation via O—H⋯N(cyano) hydrogen bonds. In the crystal, the mol­ecules pack in layers approximately parallel to the (10) plane via pairs of O—H⋯N and C—H⋯N(cyano) inter­actions.

The crystal structure of the title compound, C16H28O, features C—H⋯O hydrogen bonds making C(6) zigzag chains along one 21 screw axis. Within the limits of the data collection affected by crystal quality, the Hooft parameter gave correct indications of the known molecular chirality based on the single O atom anomalous dispersion in contrast to the indeterminate Flack value. Synthetic steps starting from manool are reported.

The structure of the title compound, C7H13N3O5, was solved using data from a multiple fragment crystal. The galactoside ring adopts a 4 C 1 chair conformation. In the crystal, the molecules are linked by strong O—H⋯O hydrogen bonds, which build linkages around the screw axis of the cell in a similar way to the iodo analogue. These C-5 and C-6 packing motifs expand to R 2 2(10), C 2 2(7) and C 2 2 2(8) motifs, as found in closely related compounds.

The title mol­ecule, C23H31NO, has two alternative cyclo­hexa­none configurations at the 4-position in a ratio of 0.663 (3):0.337 (3). The plane of the five-membered planar ring in the indolin-2-yl­idene subtends an angle of 2.19 (7)° with its fused aromatic ring, an angle of 16.24 (8)° with the plane of the major cyclo­hexa­none configuration and an angle of 8.54 (15)° with the bridging planar ethyl­idene C atoms. These last atoms subtend an angle of 8.37 (16)° with the mean plane through the major cyclo­hexa­none configuration. The mol­ecules pack approximately parallel to the (01) plane via C—H⋯π and C—H⋯O inter­actions.

The sodium salt of [immucillin-A–CO2H]− (Imm-A), namely catena-poly[[[triaqua­disodium(I)](μ-aqua)[μ-(1S)-N-car­box­yl­ato-1-(9-deaza­adenin-9-yl)-1,4-dide­oxy-1,4-imino-d-ribi­tol][triaqua­disodium(I)][μ-(1S)-N-carboxyl­ato-1-(9-deaza­aden­in-9-yl)-1,4-dide­oxy-1,4-imino-d-ribitol]] tetra­hydrate], {[Na2(C12H13N4O6)2(H2O)7]·4H2O}n, (I), forms a polymeric chain via Na+—O inter­actions involving the carboxyl­ate and keto O atoms of two independent Imm-A mol­ecules. Extensive N,O—H⋯O hydrogen bonding utilizing all water H atoms, including four waters of crystallization, provides crystal packing. The structural definition of this novel compound was made possible through the use of synchrotron radiation utilizing a minute fragment (volume ∼2.4 × 10−5 mm−3) on a beamline optimized for protein data collection. A summary of intra-ring conformations for immucillin structures indicates considerable flexibility while retaining similar intra-ring orientations.

The title mol­ecule, C24H23N3, shows some delocalization of charge based on the small [8.0 (2)°] angle between the indolin-2-yl­idene ring system and the link methyl­diazene C2N2 atom plane. A further twist of 17.2 (3)° is subtended between the C2N2 plane and its attached benzene ring. The dihedral angle between the biphenyl rings is 47.96(14)°. In the crystal, the mol­ecules pack via C—H⋯π attractive inter­actions.

In the crystal of the title compound, C7H13IO5, the molecules are linked by O—H⋯O hydrogen bonds, which build linkages around one screw axis of the cell. These C(5) and C(6) packing motifs expand to R 2 2(10) and C2 2(11) motifs and are similar to those found for closely related compounds. The galactoside ring has a 1 C 4 chair conformation.

The title compound, C12H16N4O3S·H2O, which has potential as a possible anti­malarial drug, was studied when small deviations in melting points, for two differently aged preparations, were observed. The unexpected existence of a water mol­ecule of crystallization is considered to be the cause of this variation. The 7H-pyrrolo­[2,3-d]pyrimidine unit is very slightly puckered with a total puckering amplitude of 0.035 (2) Å; its mean plane makes an angle of 88.40 (12)° with the mean plane through the ribofuranosyl unit. In the crystal, the mol­ecules are bound by strong O—H⋯N and N—H⋯O hydrogen bonds, utilizing all available protons and linking mainly through the water of crystallization.

The title compound, C34H32O6S, is an ido-configured thio­glycoside building block for heparan sulfate fragments. It contains disordered tolyl and O-benzyl groups with occupancy ratios of 0.539 (13):0.461 (13) and 0.613 (13):0.387 (13), respectively, as determined from a weakly diffracting crystal. The fused rings adopt chair conformations with the mol­ecules packing into a three-dimensional network via C—H⋯O and three C—H⋯π inter­actions. The former inter­actions, occuring between mol­ecules related by a twofold axis, define an R 2 2(26) motif.

In the title oxopyrrolidine, C15H19NO4, the five-membered pyrrolidine ring is in a twist conformation and its mean plane makes an angle of 89.2 (3)° with the phenyl ring. In the crystal, mol­ecules pack as dimers via strong O—H⋯O [R 2 2(10)] inter­actions cross-linked by weaker C—H⋯O and C—H⋯π inter­actions. Full synthetic and spectroscopic details are given for the title compound and related dicarboxyl­ates.

The title compound, C14H11BrClN3O, crystallizes with two independent mol­ecules in the asymmetric unit. In the crystal, the molecules are linked by C—N⋯Br halogen bonds, as well as weak methyl­ene C—H⋯π, phenyl C—H⋯π, C—H⋯Br and phenyl C—H⋯O(ether) inter­actions.

The title structure, C13H18O6·H2O, contains two independent 2-benzyl-myo-inositol and water mol­ecules. In the crystal, the mol­ecules are strongly hydrogen bonded into an infinite two dimensional network utilizing all OH protons.

The title compound, C3H12BN, was solved using data collected from a multiple crystal (note incomplete data shell). The cell packing is dominated by bifurcated attractive N—Hδ+⋯δ−H—B inter­actions.

The backbone of the title mol­ecule, C26H25BrN4O, is approximately planar: the dihedral angle between the planes of the indoline ring system and the furan ring is 7.68 (14)°. In the crystal, layers lying parallel to (10) occur, with the mol­ecules inter­acting via weak C—H⋯N(cyano) and C—H⋯Br bonds and short N(cyano)⋯Br contacts [3.345 (4) Å].

The title compound, [Na(C16H36BO4)]n, has a fourfold axis passing through the Na and B atoms which both are bound by four O atoms. The tetra­butoxy­borate anion provides the bridging to form one-dimensional polymers running along [001], just like those found for the tetra­ethoxy­borate structure. The two but­oxy ‘tail’ atoms are disordered over two conformations in a 0.887 (9):0.113 (9) ratio.

Mol­ecules of the title compound [systematic name: (2R,5S,7S)-2-phenyl-7-phenyl­sulfanyl-1-aza-3-oxa­bicyclo­[3.3.0]octan-8-one], C18H17NO2S, form high quality crystals even though they are only packed using C—H⋯O(carbon­yl) and weak C—H⋯S inter­actions. The dihedral angle between the aromatic rings is 85.53 (5)°. The fused rings adopt envelope and twist conformations.

The dihedral angle between the planes of two aromatic rings in the title compound [systematic name: 3-benzoyl-5-chloro-pyrimidine-2,4(1H,3H)-dione], C11H7ClN2O3, is 86.79 (6)°. Centrosymmetric dimers formed by N—H⋯O hydrogen bonds are linked through C—H⋯O inter­actions, forming a two-dimensional network parallel to (10).