نتایج جستجو برای: pyrans

تعداد نتایج: 665  

2008
Jian Tang Yang Wang Bei-Na Zhang Peng Xia

The title compound, C(13)H(13)NO(2)S, was prepared by a thermocyclization reaction from 3-methyl-6-(2-methyl-but-3-yn-2-yl-oxy)benzo[d]thia-zol-2(3H)-one. In the crystal structure, the methyl-thia-zole unit is planar, while the pyran ring assumes a screw-boat conformation. Intra-molecular C-H⋯O hydrogen bonding helps to stabilize the molecular structure.

2011
K. Swaminathan K. Sethusankar G. Sivakumar M. Bakthadoss

In the title compound C(27)H(19)ClO(6), the coumarin ring system is not exactly planar, with a dihedral angle of 4.12 (7)° between its benzene and lactone rings. The cis-fused pyran rings adopt half-chair conformations. The carbometh-oxy and chloro-phenyl groups are in a trans configuration. The crystal packing is stabilized by inter-molecular C-H⋯O interactions, which produce a centrosymmetric...

2013
N. Latha J. Naga Siva Rao R. Raghunathan G. Divya S. Lakshmi

In the title compound, C23H23NO8, the dihedral angle between the five- and six-membered rings of the indene-dione moiety is 3.09 (13)°. The mean plane of the five-membered ring (which has a flat envelope conformation with the spiro C atom as the flap) is inclined to the mean plane of the central five-membered ring of the pyrrolizine unit by 76.48 (12)°. This central ring has a twist conformatio...

2010
B. Gunasekaran S. Kathiravan R. Raghunathan V. Manivannan

In the title compound, C(24)H(22)ClNO(3), the dihedral angle between the naphthalene ring system and the chloro-phenyl ring is 67.44 (4)°. The pyrrolidine and dihydro-pyran rings exhibit envelope and half chair conformations, respectively. In the crystal structure, weak C-H⋯π inter-actions are observed.

2012
D. Lakshmanan S. Murugavel D. Kannan M. Bakthadoss

In the title compound, C(27)H(24)N(2)O(3), the pyrroldine ring adopts a twist conformation, while the six-membered pyran-one ring of the coumarin ring system is in a sofa conformation. In the crystal, pairs of N-H⋯O hydrogen bonds link the mol-ecules into inversion R(2) (2)(8) dimers. These dimers are further connected via C-H⋯O hydrogen bonds.

2014
Zeynep Gültekin Mehmet Civan Wolfgang Frey Tuncer Hökelek

The asymmetric unit of the title compound, C26H28O6·2CH3OH, contains two independent methyl 6-O-trityl-α-d-gluco-pyran-oside mol-ecules and four methanol solvent mol-ecules. The rings of two methyl α-d-gluco-pyran-oside adopt chair conformations. In the crystal, extensive intra- and inter-molecular O-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional supra-molecular archi...

2012
K. Swaminathan K. Sethusankar J. Srinivasan M. Bakthadoss

In the title compound, C(24)H(20)N(2)O(2), the six-membered pyran ring adopts a half-chair conformation with one C atom deviating from the mean plane of the remaining ring atoms by 0.654 (6) Å. The five-membered isoxazole ring adopts an N-envelope conformation with the N atom displaced by 0.742 (5) Å from the mean plane formed by the remaining ring atoms. The carbonitrile side chain is almost l...

2012
P. Rajalakshmi N. Srinivasan R. V. Krishnakumar

In the title compound, C(21)H(20)N(2)O, the piperidine ring adopts a chair conformation while the pyran ring adopts a screw-boat conformation. The piperidine ring forms dihedral angles of 65.75 (3) and 67.79 (5)° with the chroman and methyl-substituted benzene rings, respectively. The crystal structure features weak C-H⋯π and π-π [centroid-centroid distance = 3.8098 (8) Å] inter-actions.

2014
Yoshinobu Ishikawa

In the title compound, C10H5ClO3, a chlorinated 3-formyl-chromone derivative, all atoms are essentially coplanar (r.m.s. deviation = 0.032 Å for the non-H atoms), with the largest deviation from the least-squares plane [0.0598 (14) Å] being for a pyran-ring C atom. In the crystal, mol-ecules are linked through stacking inter-actions along the b axis [shortest centroid-centroid distance between ...

2013
P. Rajalakshmi N. Srinivasan R. V. Krishnakumar

The title compound, C17H19N3O2, crystallizes with two independent mol-ecules (A and B) in the asymmetric unit. In both mol-ecules, the pyran ring has a twisted conformation ((5)S4), with Q = 0.301 (3) Å, θ = 116.7 (6) and ϕ= 213.6 (7)° for mol-ecule A, and Q = 0.364 (2) Å, θ = 113.7 (3) and ϕ = 213.0 (4)° for mol-ecule B. In mol-ecule B, the terminal ethyl group is disordered over two orientati...

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