نتایج جستجو برای: Chromane

تعداد نتایج: 58  

2010
Kwang-Su Choi Sung-Gon Kim

The title compound, C(17)H(13)ClO(2), was obtained from the oxidation of 6-chloro-4-(2-phenyl-ethen-yl)chroman-2-ol, which was synthesized by the reaction of of (E)-3-(5-chloro-2-hy-droxy-phen-yl)acryl-aldehyde with styrylboronic acid using diethyl-amine as a catalyst. The six-membered pyran-one ring of the chromane system has a screw-boat conformation. The dihedral angle between the least-squa...

Journal: :Dalton transactions 2007
Vita M Vecchio Michele Benedetti Danilo Migoni Sandra A De Pascali Antonella Ciccarese Santo Marsigliante Francesco Capitelli Francesco P Fanizzi

We were able, for the first time, to synthesize and characterize Pt derivatives with a structural shape similar to vitamin E, having a metalla-chromane core. The formation reaction mechanism includes an unexpected highly selective ortho aromatic electrophilic substitution on phenol, operated by [PtCl(eta(1)-C(2)H(4)OR)(N-N)], R = Me or Ph, and a final cyclization step. The X-ray structure of on...

Journal: :Molecules 2009
Ataru Kobayashi Gen-ichi Konishi

Synthesis and characterization of resorcinol-acetone copolymer is described. The polymer was prepared by trifluoroacetic acid-catalyzed polymerization of resorcinol with acetone. According to the (1)H-NMR, (13)C-NMR, and MALDI-TOF Mass spectra data, the obtained polymer had three types of repeating units: isopropylidene bridged-resorcinol, chromane ring, and spiro-shaped double chromane ring, i...

Journal: :Science 1938
O H Emerson

By oxidizing alpha tocopherol with chromic anhydride in acetic acid solution, a lactone C21H4002 was obtained. The origin of such a lactone is easily explicable on the theory that alpha tocopherol contains a chromane ring; if alpha tocopherol contained a coumarane ring, a beta hydroxy acid would be expected. Karrer and his co-workers,2 by treating pseudo cumo hydroquinone with phytyl bromide, o...

2012
Ishmael B Masesane Zelalem Yibralign Desta

The reported methodologies for the synthesis of chromane derivatives through the reaction of salicylaldehyde and enolates are discussed. The enolates and their equivalents involved in the reactions discussed in this article were derived from ketones, nitroalkanes, malononitrile and α,β-unsaturated compounds.

Journal: :Catalysts 2022

An organocatalytic [4 + 2] cascade annulation of salicylaldehydes and 1,3-bisarylsulfonylpropenes has been developed. This protocol enables the efficient straightforward synthesis a new series 3-sulfonyl-2-sulfonylmethyl-2H-chromenes that are useful for exploring pharmacologically valued compounds. Further reductive modifications result in 3-desulfonylated chromene or chromane derivatives. can ...

Journal: :International journal for parasitology. Drugs and drug resistance 2016
Bracken F Roberts Iredia D Iyamu Sukjun Lee Eunyoung Lee Lawrence Ayong Dennis E Kyle Yu Yuan Roman Manetsch Debopam Chakrabarti

We screened a collection of synthetic compounds consisting of natural-product-like substructural motifs to identify a spirocyclic chromane as a novel antiplasmodial pharmacophore using an unbiased cell-based assay. The most active spirocyclic compound UCF 201 exhibits a 50% effective concentration (EC50) of 350 nM against the chloroquine-resistant Dd2 strain and a selectivity over 50 using huma...

2013
Ahmed Jashari Emil Popovski Bozhana Mikhova Rositsa P. Nikolova Boris L. Shivachev

In the title compound, C(16)H(15)N(3)O(4), the dihedral angle between the chromane and isoxazole rings [r.m.s. deviations = 0.042 and 0.007 Å, respectively] is 20.33 (12)°. The mol-ecular geometry is stabilized by an intra-molecular N-H⋯O hydrogen bond. In the crystal, N-H⋯O hydrogen bonds generate chains along the c-axis direction. The crystal studied was a non-morohedral twin.

Journal: :Organic & biomolecular chemistry 2014
Marcin Górecki Agata Suszczyńska Magdalena Woźnica Aneta Baj Michał Wolniak Michał K Cyrański Stanisław Witkowski Jadwiga Frelek

The validity of the chromane helicity rule correlating the sense of twist within the dihydropyran ring with the CD sign of the (1)Lb band observed at ca. 290 nm in their electronic circular dichroism (ECD) spectra is examined using a set of natural (S)-trolox derivatives. To investigate both the scope and the limitations of the rule a combination of ECD spectroscopy, especially the temperature ...

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