Methyl 4,5-diacet­oxy-1-oxo-2-phenyl­perhydro-4,6-epoxy­cyclo­penta­[c]pyridine-7-carboxyl­ate ethanol solvate

The title compound, the product of an acid-catalysed Wagner–Meerwein skeletal rearrangement, crystallizes as an ethanol monosolvate, C20H21NO8·C2H6O. The title mol­ecule comprises a fused tricyclic system containing two five-membered rings (cyclo­pentane and tetra­hydro­furan) in the usual envelope conformations and one six-membered ring (piperidinone) adopting a flattened twist–boat conformation

Methyl 7,8-diacet­oxy-11-oxo-5-(2-oxo­pyrrolidin-1-yl)-7,9-epoxy­cyclo­penta­[4,5]pyrido[1,2-a]quinoline-10-carboxyl­ate sesquihydrate

The title compound, C26H28N2O9·1.5H2O, the product of an acid-catalysed Wagner–Meerwein skeletal rearrangement, crystallizes as a sesquihydrate with the O atom of one of the two independent water mol­ecules occupying a special position on a twofold axis. The organic mol­ecule comprises a fused penta­cyclic system containing two five-membered rings (cyclo­pentane and tetra­hydro­furan) and three six-membered rings (piperidinone, tetra­hydro­pyridine and benzene). The five-membered rings have the usual envelope conformations, and the central six-membered piperidinone and tetra­hydro­pyridine rings adopt boat and sofa conformations, respectively. In the crystal, there are three independent O—H⋯O hydrogen bonds, which link the organic mol­ecules and water mol­ecules into complex two-tier layers parallel to (001). The layers are further linked into a three-dimensional framework by attractive inter­molecular carbon­yl–carbonyl inter­actions

Raise the anchor! Synthesis, X-ray and NMR characterization of 1,3,5-triazinanes with an axial tert-butyl group

N-t-Bu-N’,N’’-disulfonamide-1,3,5-triazinanes were synthesized and characterized by X-ray single crystal structure analysis. In the course of the X-ray structure elucidation, the first solid experimental evidence of the axial position of the tert-butyl group in unconstrained hexahydro-1,3,5-triazacyclohexanes was obtained. Dynamic low-temperature NMR analysis allowed to fully investigate a rare case of crystallization-driven unanchoring of the tert-butyl group in the chair conformation of saturated sixmembered cycles. DFT calculations show that the use of explicit solvent molecules is necessary to explain the equatorial position of the t-Bu group in solution. Otherwise, the axial conformer is the thermodynamically stable isomer.Fil: Kletskov, Alexey V.. University of Russia; RusiaFil: Zatykina, Anastasya D.. University of Russia; RusiaFil: Grudova, Mariya V.. University of Russia; RusiaFil: Sinelshchikova, Anna A.. Academy of Sciences; RusiaFil: Grigoriev, Mikhail. Academy of Sciences; RusiaFil: Zaytsev, Vladimir P.. University of Russia; RusiaFil: Gil, Diego Mauricio. Universidad Nacional de Tucumán. Instituto de Biotecnología Farmacéutica y Alimentaria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biotecnología Farmacéutica y Alimentaria; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Orgánica; ArgentinaFil: Novikov, Roman A.. Academy of Sciences; RusiaFil: Zubkov, Fedor Ivanovich. University of Russia; RusiaFil: Frontera, Antonio. Universidad de las Islas Baleares; Españ

Intramolecular sp2-sp3 disequalization of chemically identical sulfonamide nitrogen atoms: single crystal X-Ray diffraction characterization, hirshfeld surface analysis and DFT calculations of N-substituted hexahydro-1,3,5-triazines

In this manuscript, the synthesis and single crystal X-ray diffraction characterization of four N-substituted 1,3,5-triazinanes are reported along with a detailed analysis of the noncovalent interactions observed in the solid state architecture to these compounds, focusing on C–H···π and C–H···O H-bonding interactions. These noncovalent contacts have been characterized energetically by using DFT calculations and also by Hirshfeld surface analysis. In addition, the supramolecular assemblies have been characterized using the quantum theory of “atoms-in-molecules” (QTAIM) and molecular electrostatic potential (MEP) calculations. The XRD analysis revealed a never before observed feature of the crystalline structure of some molecules: symmetrically substituted 1,3,5-triazacyclohexanes possess two chemically identical sulfonamide nitrogen atoms in different sp2 and sp3-hybridizations.Fil: Kletskov, Alexey V.. University of Russia; RusiaFil: Gil, Diego Mauricio. Universidad Nacional de Tucumán. Instituto de Biotecnología Farmacéutica y Alimentaria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biotecnología Farmacéutica y Alimentaria; ArgentinaFil: Frontera, Antonio. Universidad de las Islas Baleares; EspañaFil: Zaytsev, Vladimir P.. University of Russia; RusiaFil: Merkulova, Natalia L.. University of Russia; RusiaFil: Beltsova, Ksenia R.. University of Russia; RusiaFil: Sinelshchikova, Anna A.. University of Russia; RusiaFil: Grigoriev, Mikhail S.. University of Russia; RusiaFil: Grudova, Mariya V.. University of Russia; RusiaFil: Zubkov, Fedor I.. University of Russia; Rusi

(6aS*,6bS*,11R*,11aR*)-6-(2-Furyl­methyl)-5,12-dioxo-5,6,6a,6b,7,11,11a,12-octa­hydro­furo[3′,2′:5,6]isoindolo[2,1-a]quinazoline-11-carb­oxy­lic acid

The title compound, C23H18N2O6, is the product of an intra­molecular thermal cyclo­addition within 1-malein-2-[(E)-2-(2-fur­yl)vin­yl]-4-oxo-3,4-dihydro­quinazoline. The mol­ecule comprises a previously unknown fused penta­cyclic system containing two five-membered rings (2-pyrrolidinone and furan) and three six-membered rings (benzene, 2,3-dihydro-4-pyrimidinone and dihydro­cyclo­hexa­ne). The central five-membered pyrrolidinone ring has the usual envelope conformation. The six-membered dihydro­pyrimidinone and dihydro­cyclo­hexane rings adopt a half-boat and a half-chair conformation, respectively. The dihedral angle between the planes of the terminal benzene and furan rings is 45.99 (7)°. In the crystal, O—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers. Weak C—H⋯O hydrogen bonds consolidate further the crystal packing, which exhibits π–π inter­actions, with a short distance of 3.556 (3) Å between the centroids of benzene rings of neighbouring mol­ecules

Helicobacter pylori Diagnostic Tests Used in Europe : Results of over 34,000 Patients from the European Registry on Helicobacter pylori Management

Funding Information: This study was funded by Richen; however, clinical data were not accessible and the company was not involved in any stage of the Hp-EuReg study (design, data collection, statistical analysis, or manuscript writing). We want to thank Richen for their support. This project was promoted and funded by the European Helicobacter and Microbiota Study Group (EHMSG), the Spanish Association of Gastroenterology (AEG) and the Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd). The Hp-EuReg was co-funded by the European Union programme HORIZON (grant agreement number 101095359) and supported by the UK Research and Innovation (grant agreement number 10058099). The Hp-EuReg was co-funded by the European Union programme EU4Health (grant agreement number 101101252). Acknowledgments We want to especially thank Sylva-Astrik Torossian for her assistance in language editing. Natalia García Morales is the first author who is acting as the submission’s guarantor. All authors approved the final version of the manuscript.Peer reviewedPublisher PD

rac-Methyl (3aR*,4S*,5R*,7aR*)-5,7a-bis(acetyloxy)-3-oxo-2-phenyloctahydro-1H-isoindole-4-carboxylate

The title molecule, C20H23NO7, the product of nucleophilic cleavage of the 3a,6-epoxy bridge in 1-oxo-2-phenyloctahydro-3a,6-epoxyisoindole-7-carboxylate, comprises a cis-fused bicyclic system containing a 2-pyrrolidinone ring in an envelope conformation (with the C atom bearing the carboxylate substituent as the flap) and a cyclohexane ring in a chair conformation. The carboxylate substituent occupies the equatorial position, whereas the two acetyloxy substituents are in axial positions. The N atom has a trigonal-planar geometry, the sum of the bond angles being 359.3 (3)°. The dihedral angle between the mean plane of the four planar atoms of the pyrrolidinone ring and the phenyl ring is 25.98 (6)°. In the crystal, molecules are linked into zigzag chains along the c-axis direction by C—H...O hydrogen bonds

Interaction between maleic acid and N-R-furfurylamines: crystal structure of 2-methyl-N-[(5-phenylfuran-2-yl)methyl]propan-2-aminium (2Z)-3-carboxyacrylate and N-[(5-iodofuran-2-yl)methyl]-2-methylpropan-2-aminium (2Z)-3-carboxyprop-2-enoate

The title molecular salts, C15H20NO+·C4H3O4−, (I), and C9H15INO+·C4H3O4−, (II), have very similar molecular geometries for both cation and anion. The anions of both (I) and (II) are practically planar (r.m.s. deviations = 0.062 and 0.072 Å, respectively) and adopt a rare symmetrical geometry with the hydroxy H atom approximately equidistant from the two O atoms. In their crystals, the cations and anions in both (I) and (II) form tight ionic pairs via strong N—H...O hydrogen bonds, with a roughly perpendicular disposition of the anion to the furan ring of the cation. This ion-pair conformation appears to correlate with the lack of reactivity of these salts in [4 + 2] cycloaddition reactions. In the extended structures of (I) and (II), the ion pairs form hydrogen-bonded chains propagating along [010] and [001], respectively, via N—H...O hydrogen bonds