نتایج جستجو برای: pyran
تعداد نتایج: 1454 فیلتر نتایج به سال:
In the title compound, C25H27FO3, each of the cyclo-hexenone rings adopts a half-chair conformation, whereas the six-membered pyran ring adopts a flattened boat conformation, with the O and methine C atoms deviating by 0.0769 (15) and 0.196 (2) Å, respectively, from the plane of the other four atoms (r.m.s. deviation = 0.004 Å). The C=C double bond adopts an E conformation. The dihedral angle b...
The natural product saudin was found to induce hypoglycemia in mice and, therefore, could be an appealing lead structure for the development of new agents to treat diabetes. A diastereoselective tandem Stille-oxa-electrocyclization reaction has been developed which provides access to the core structure of saudin in a rapid and convergent manner. This new reaction has been extended to the conver...
In the title compound, C30H29BrN2O5, the β-lactam ring is essentially planar, with the O atom displaced from this plane by 0.856 (9) Å, and forming dihedral angles of 24.35 (13) and 89.42 (14)° with the planes of the benzene substituent groups on this ring. The tetra-hydro-pyran ring adopts an envelope conformation with the C atom bearing the β-lactam ring as the flap. In the crystal, weak C-H⋯...
In the title compound, C(16)H(16)ClNO(2)S(2), the piperidine ring is in a chair conformation. In the coumarin ring system, the dihedral angle between the benzene and pyran rings is 3.5 (1)°. In the crystal, a weak C-H⋯O hydrogen bond links mol-ecules into chains along [001]. In addition, π-π stacking inter-actions are present involving the benzene and pyran rings, with a centroid-to-centroid di...
In the title compound, C11H8O3, the fused-ring system is almost planar (r.m.s. deviation = 0.020 Å), with the largest deviation from the least-squares plane [0.0462 (17) Å] being for a pyran C atom. The dihedral angle between the plane of the fused-ring system and acetyl plane is 5.149 (16)°. In the crystal, the fused rings are linked by aromatic π-π stacking inter-actions [centroid-centroid di...
The structure of a representative pyrazolo[3,4]pyran derivative was determined by 1D and 2D NMR techniques. Complete 1H and 13C chemical shifts for this compound are reported. Careful analysis of the HMBC (Heteronuclear Multi-Bond Correlation) spectrum helped to elucidate the configuration of the derivative around C7 and C8. The results showed that the characteristic double-strong and double-we...
In the title compound, tetra-hydro-seselin, C14H16O3, a pyran-ocoumarin [systematic name: 8,8-dimethyl-3,4,9,10-tetra-hydro-2H,8H-pyrano[2,3-f]chromen-2-one] obtained from the hydrogenation of seselin in the presence of Pd/C in MeOH at room temperature, the dihedral angle between the central benzene ring and the best planes of the outer fused ring systems are 6.20 (7) and 10.02 (8)°. In the cry...
Phelligridin G is an unusual natural product that contains an embedded spiro-fused furanone core. We have investigated two furan-based synthetic approaches towards the spirocyclic core structure of this natural product from readily available 2-phenylfurans. Although initial studies involving an oxidative cyclization were unsuccessful, we were ultimately able to access this key system through ...
Abstract A series of new azo disperse dyes was synthesized by coupling 4-hydroxy-6-methyl-2H-pyran-2-one (triacetic acid lactone, TAL) or its hydrogenated derivative 4-hydroxy-6-methyl-5,6-dihydro-2H-pyran-2-one (dihydro triacetic DHTAL) with diazonium salts derived from aniline, 4-bromoaniline, 4-nitroaniline, 4-methoxyaniline, 2,4-dimethoxyaniline and 2,5-dimethoxyaniline. Spectroscopic data ...
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