ABSTRACT: The main structural unit of the title compoud, C(21)H(18)O(6), is a fused three-ring group consisting of coumarin and tetra-hydro-pyrane ring systems. Two C atoms of the tetra-hydro-pyran ring are displaced by 0.295?(3) and -0.360?(2)?Å from the mean plane of coumarin ring. The dihedral angle between the phenyl and coumarin rings is 73.94?(3)°. Inter-molecular O-H?O hydrogen bonds are present in the crystal structure.
Project description:The title compound, C(21)H(17)ClO(6), is optically pure and adopts an R configuration. It was obtained by an organocatalytic asymmetric Michael addition of 4-hydroxy-coumarin with (E)-ethyl 4-(4-chloro-phen-yl)-2-oxobut-3-enoate. The structure consists of a tetra-hydro-pyran unit fused to the coumarin ring ring system. The hydroxyl and phenyl groups are on the same side of the tetra-hydro-pyrane ring. The benzene ring is almost perpendicular to the coumarin ring [dihedral angle of 72.89?(3)°]. In the crystal structure, inter-molecular O-H?O hydrogen bonds are observed. An intra-molecular O-H?O contact also occurs.
Project description:The asymmetric unit of the title compound, C28H38N4O8·C2H6OS, contains one tetra-peptide and one disordered dimethyl sulfoxide (DMSO) mol-ecule. The central five-membered ring (Pro(2)) of the peptide mol-ecule has a disordered envelope conformation [occupancy ratio 0.879?(2):0.121?(2)] with the envelope flap atom, the central C atom of the three ring methylene groups, lying on alternate sides of the mean ring plane. The terminal five-membered ring (Pro(4)) also adopts an envelope conformation with the C atom of the methylene group closest to the carboxylic acid function as the envelope flap, and the six-membered tetra-hydro-pyrane ring shows a chair conformation. The tetra-peptide exists in a helical conformation, stabilized by an intra-molecular hydrogen bond between the amide N-H group of the heterocyclic ?-amino acid Thp and the amide O atom of the 4-meth-oxy-benzoyl group. This inter-action has a graph set motif of S(10) and serves to maintain a fairly rigid ?-turn structure. In the crystal, the terminal hy-droxy group forms a hydrogen bond with the amide O atom of Thp of a neighbouring mol-ecule, and the amide N-H group at the opposite end of the mol-ecule forms a hydrogen bond with the amide O atom of Thp of another neighbouring mol-ecule. The combination of both inter-molecular inter-actions links the mol-ecules into an extended three-dimensional framework.
Project description:The asymmetric unit of the title compound, C(13)H(9)NO(3), consists of two crystallographically independent mol-ecules. In each mol-ecule, the tetra-hydro-furan (THF) ring adopts an envelope conformation with one of the methyl-ene C atoms positioned at the flap. The dihedral angles between the mean plane of the THF and the benzofuran ring system are 70.85?(5) and 89.59?(6)°. In the crystal, mol-ecules are stacked in a column along the a-axis direction through C-H?O hydrogen bonds, with columns further linked by C-H?N and C-H?O inter-actions.
Project description:The title compounds, C22H29NO2 (3) and C22H29NO2 (4) [systematic names: (1S*,2R*)-7-meth-oxy-2-methyl-3-(4-phenyl-but-yl)-2,3,4,5-tetra-hydro-1H-3-benzazepin-1-ol and (1R*,2R*)-7-meth-oxy-2-methyl-3-(4-phenyl-but-yl)-2,3,4,5-tetra-hydro-1H-3-benzazepin-1-ol, are diastereomers with the relative configuration of the adjacent hydroxyl and methyl groups at the seven-membered azepine ring being trans in (3) and cis in (4). In the crystals the orientation of these groups is -anti-periplanar (3) and +syn-clinal (4). In both cases, the crystals studied proved to be of a racemic mixture, with relative configurations (R*,S*)-3 and (R*,R*)-4. In both compounds, the seven-membered azepine ring has a chair-like conformation, and the 4-phenyl-butyl side chain adopts a extended conformation in (R*,S*)-3, but a twisted conformation in (R*,R*)-4. In the crystal of (S*,R*)-3, mol-ecules are linked via C-H?O hydrogen bonds, forming slabs parallel to the ac plane. In the crystal of (R*,R*)-4, mol-ecules are linked via O-H?N hydrogen bonds, forming chains propagating along the c-axis direction. The chains are linked by C-H?O hydrogen bonds, forming slabs parallel to the ac plane.
Project description:In the title compound, C22H24N2O6, the indole ring has a twist conformation and the tetra-hydro-2H-pyran-2-one ring a half-chair conformation. One of the pyrrolidine rings adopts an envelope conformation on the N atom, while the other has a twist conformation; the 'butterfly' angle between their mean planes is 62.98?(11)°. The dioxolane ring adopts a twist conformation and the tetra-hydro-furan ring has an envelope conformation on the C atom in the fused tetra-hydro-2H-pyran-2-one ring adjacent to the O atom of the tetra-hydro-furan ring. The 'butterfly' angle between the mean planes of these two five-membered rings is 69.14?(10)°. In the crystal, mol-ecules are linked by N-H?O hydrogen bonds, forming chains along the a axis.
Project description:The title di-epoxy-phenalene derivative, C17H18O6, comprises a fused cyclic system containing four five-membered rings (two di-hydro-furan and two tetra-hydro-furan) and one six-membered ring (cyclo-hexa-ne). The five-membered di-hydro-furan and tetra-hydro-furan rings adopt envelope conformations, and the six-membered cyclo-hexane ring adopts a distorted chair conformation. Two methyl carboxyl-ate groups occupy adjacent positions (2- and 3-) on a tetra-hydro-furan ring. In the crystal, two pairs of C-H⋯O hydrogen bonds link the mol-ecules to form inversion dimers, enclosing two R 2 2(6) ring motifs, that stack along the a-axis direction and are arranged in layers parallel to the bc plane.
Project description:In the title compound, C(23)H(21)NO(3)S, the piperidine ring of the tetra-hydro-isoquinolinone unit adopts a screw-boat conformation. The thio-phene ring is disordered in a 0.700?(3):0.300?(3) ratio by an approximate 180° rotation of the ring around the C-C bond linking the ring to the tetra-hydro-isoquinolinone unit. The benzene ring of the tetra-hydro-isoquinolinone unit makes dihedral angles of 83.1?(2) and 62.38?(11)° with the major occupancy thio-phene ring and the phenyl ring, respectively. The dihedral angle between the phenyl ring and the thio-phene ring is 71.0?(2)°. In the crystal structure, mol-ecules are linked together by inter-molecular C-H?O and C-H?? inter-actions.
Project description:<h4>The title compound (systematic name</h4>7-oxo-3-phenyl-2,6-dioxabicyclo-[3.3.1]nonan-4-yl acetate), C(15)H(16)O(5), is a styryllactone derivative which was isolated from Goniothalamus macrophyllus. The mol-ecule has two fused rings consisting of a tetra-hydro-2H-pyran and a lactone ring, with the benzene ring and the acetyl group attached to the tetra-hydro-2H-pyran ring. The tetra-hydro-2H-pyran ring is in a standard chair conformation, whereas the lactone ring is in an envelope conformation. In the crystal, mol-ecules are linked by weak C-H?O inter-actions into sheets parallel to the ac plane. Weak C-H?? inter-actions are also observed.
Project description:The title compound, C33H35N3O5, is the product of the multicomponent condensation of 1-benzyl-4-eth-oxy-carbonyl-piperidin-3-one with 1,5-bis-(2-formyl-phen-oxy)-3-oxapentane and ammonium acetate. The mol-ecule comprises a penta-cyclic system containing the aza-14-crown-4-ether macrocycle, tetra-hydro-pyrimidine, tetra-hydro-pyridine and two benzene rings. The aza-14-crown-4-ether ring adopts a bowl conformation with a dihedral angle of 62.37?(5)° between the benzene rings. The tetra-hydro-pyrimidine ring has an envelope conformation with the chiral C atom as the flap, whereas the tetra-hydro-pyridine ring adopts a distorted chair conformation. Two amino groups are involved in intra-molecular N-H?O hydrogen bonds. In the crystal, weak C-H?O hydrogen bonds link the mol-ecules into layers parallel to the ab plane.
Project description:The title compound, C(22)H(18)ClN(3)S, was synthesized by the reaction of 4-chloro-benzaldehyde, tetra-hydro-thio-pyran-4-one and 3-methyl-1-phenyl-1H-pyrazol-5-amine in acetic acid without a catalyst. The pyridine and pyrazole rings are almost coplanar, the dihedral angle between their mean planes being 2.50?(1)°. The thio-pyran ring exhibits an envelope conformation. The crystal packing is stabilized by inter-molecular C-H?Cl hydrogen bonds and by C-H?? and ?-? inter-actions [centroid-centroid distances of 3.825?(2)?Å between pyridine rings and 3.557?(2)?Å between pyrazole and pyridine rings.