نتایج جستجو برای: membered rings
تعداد نتایج: 52672 فیلتر نتایج به سال:
THE TITLE COMPOUND [SYSTEMATIC NAME: 6β,10-dihy-droxy-1α,14α,16β-trimeth-oxy-4-methyl-7β,8-(methyl-enedi-oxy)-20-ethyl-aconitan-6-yl acetate], C(27)H(41)NO(8), is a C(19)-diterpenoid alkaloid and a major diterpenoid alkaloid component of the roots of Delphinium delavayi Franch. var. pogonanthum (Hand.-Mazz.) W. T. Wang. The mol-ecule has a lycoctonine carbon-atom skeleton with four six-membered...
The title compound, C48H75B3Cl6O3, was synthesized in two steps from β-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzo-cyclo-hept-ene), which was isolated from the essential oil of the Atlas cedar (Cedrus Atlantica). The mol-ecule consists of an almost planar cyclo-triboroxane ring [maximum deviation = 0.036 (2) Å] linked to three identical fused ring systems with different c...
This work introduces a new local aromaticity measure, defined as the mean of Bader's electron delocalization index (DI) of para-related carbon atoms in six-membered rings. This new electronic criterion of aromaticity is based on the fact that aromaticity is related to the cyclic delocalized distribution of pi-electrons. We have found that this DI and the harmonic oscillator model of aromaticity...
The title compound TNDFIW, C(8)H(8)N(10)O(10), is a caged heterocycle substituted with four nitro and two formyl groups. It is related to the hexa-azaisowurtzitane family of high-density high-energy polycyclic cage compounds. Four nitro groups are appended to the four N atoms of the two five-membered rings, while the other two formyl groups are attached to the two N atoms of the six-membered ri...
Density functional theory calculations were performed to investigate the endohedral and exohedral adsorption of a H2 molecule on the classical and nonclassical fullerenes Cx (x=58, 59, 60, 62) with seven-, eight-, and ninemembered rings. The amplitude of adsorption energies are within 0.03eV and the molecule-fullerene interaction belongs to van der Waals type. Penetration of a H2 molecule throu...
N-{[2,5-Dichloro-4-(1,1,2,3,3,3-hexafluoropropoxy)phenyl]aminocarbonyl}-2,6-difluorobenzamide
In the mol-ecule of the title compound, C(17)H(8)Cl(2)F(8)N(2)O(3), the two aromatic rings are oriented at a dihedral angle of 50.12 (3)°. Intra-molecular N-H⋯O, C-H⋯O and N-H⋯Cl hydrogen bonds result in the formation of two six- and one five-membered rings. The six-membered rings have flattened-boat conformations, while the five-membered ring adopts an envelope conformation. In the crystal str...
The title mol-ecule, C(28)H(28)Cl(4)N(6)O(6), is built up from four fused rings, viz. two nearly planar imidazole five-membered rings which adopt envelope conformations with the C=O groups at the flap position, and two triazine six-membered rings which adopt chair conformations. Each six-membered ring has a 2,4-dichloro-benzyl substituent attached to an N atom. In the mol-ecule, the two ethyl g...
The title compound, C(17)H(22)O(6), was semi-synthesized from 9-hy-droxy-arthenolide, which was isolated from the chloro-form extract of the aerial parts of Anvillea radiata. The mol-ecule contains fused five- and ten-membered rings: the five-membered lactone ring has a twisted conformation, whereas the ten-membered ring displays an approximate chair-chair conformation. The dihedral angle betwe...
The title compound, C16H24Br2O, was synthesized from the reaction of β-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzo-cyclo-heptene), which was isolated from Atlas cedar (Cedrus atlantica). The asymmetric unit contains two independent mol-ecules with similar conformations. Each mol-ecule is built up from two fused seven-membered rings and an additional three-membered ring. I...
The title compound, C(16)H(22)Cl(2), a derivative of β-himachalene, was semi-synthesized from natural essential oils of Cedrus atlantica. The mol-ecule is built up from two fused six- and seven-membered rings. The six-membered ring has a perfect chair conformation, whereas the seven-membered ring displays a screw boat conformation; the dihedral angle between the rings is 46.48 (9)°.
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