نتایج جستجو برای: pyran annulated hetrocyclic systems
تعداد نتایج: 1185076 فیلتر نتایج به سال:
The title compound, C23H20N2O6, crystallizes with two mol-ecules in the asymmetric unit in which the dihedral angles between the mean planes of the pyran and phenyl rings are 66.6 (1) and 61.9 (1) °. The fused pyrone and pyran rings each adopts a sofa conformation. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules, forming a two-dimensional network parallel to [001].
The title compound, C(21)H(21)ClO(7)·C(2)H(5)OH was synthesized by the condensation reaction between helicid [systematic name: 4-(β-d-allopyranos-yloxy)benzaldehyde] and 4-chloro-aceto-phen-one in ethanol. In the mol-ecular structure, the pyran-oside ring adopts a chair conformation. In the crystal structure, the molecules are linked by inter-molecular O-H⋯O hydrogen bonds involving the OH grou...
The title compound, C(26)H(24)O(3), was synthesized via the coupling of 2-methoxy-benzaldehyde, 2-naphthol and 5,5-dimethyl-cyclo-hexane-1,3-dione. The pyran ring adopts a boat conformation, while the cyclo-hexenone ring is in an envelope conformation. The 2-methoxy-phenyl ring is almost perpendic-ular to the plane through the four C atoms of the pyran ring [dihedral angle = 88.76 (9)°].
In the mol-ecule of the title compound, C(16)H(13)N(3)O(4), the atoms of the spiro pyran ring are nearly planar with a maximum deviation of 0.095 (2) Å. The indole and pyran rings are oriented at a dihedral angle of 87.3 (9)°. In the crystal, mol-ecules are linked by inter-molecular N-H⋯N and N-H⋯O hydrogen bonds.
A novel bicyclization of 2-(2-(hydroxymethyl)-1-methylene-2,3-dihydro-1H-inden-2-yl)ethanol with aldehydes in the presence of 10 mol% BF3·OEt2 in dichloromethane at 0-25 °C affords the biologically relevant indeno[2,1-c]pyran scaffolds in good yields with high selectivity. Similarly the bicyclization of 2-(1-(hydroxymethyl)-2-methylenecyclopentyl)ethanol with aldehydes generates the correspondi...
Heating 4-methoxy-1-naphthol with a 1,1-diarylprop-2-yn-1-ol gave the 2,2-diaryl-6-methoxy-2H-naphtho[1,2-b]pyran together with the novel merocyanine, (E)-2-[3',3'-bis(aryl)allylidene]-4-methoxynaphthalen-1(2H)-one. Brief UV-irradiation of the pyran favoured the formation of the (Z)-merocyanine with longer irradiation and/or acidic conditions favouring the (E)-isomer.
The title compound, C(25)H(23)NO(5), comprising two stereogenic carbon atoms of the same configuration, crystallizes in a centrosymmetric space group as a racemate. The six-membered pyran ring and the five-membered isoxazole ring adopt sofa and twisted conformations, respectively. The dihedral angle between the benzene ring and the mean plane through the near coplanar atoms of the pyran ring is...
In the mol-ecular structure of the title compound, C(25)H(21)NO(4), the pyran ring adopts a flattened boat conformation, while the cyclo-hexenone ring is in an envelope conformation. The 4-nitro-phenyl ring is almost perpendicular to the pyran ring [dihedral angle = 89.39 (1)°]. In the crystal, mol-ecules are connected by inter-molecular C-H⋯O hydrogen bonds.
InCl3-driven regioselective synthesis of functionalized/annulated quinolines: scope and limitations.
The efficient, regioselective synthesis of functionalized/annulated quinolines was achieved by the coupling of 2-aminoaryl ketones with alkynes/active methylenes/α-oxoketene dithioacetals promoted by InCl(3) in refluxing acetonitrile as well as under solvent-free conditions in excellent yields. This transformation presumably proceeded through the hydroamination-hydroarylation of alkynes, and t...
The study of binding interaction between pyrimidine-annulated spiro-dihydrofuran (PSDF) with calf thymus DNA (CTDNA) using UV absorption, fluorescence, circular dichroism (CD), and molecular docking methods. The experimental results revealed that PSDF preferred to bind to the groove of CTDNA with the binding constant (K) of 1.51×102 L/mol at 293 K. Based on the signs and magnitudes of the entha...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید