نتایج جستجو برای: 2h pyrans

تعداد نتایج: 11400  

Journal: :Molecules 2016
Mei-Huey Lin Kung-Yu Liang Chang-Hsien Tsai Yu-Chun Chen Hung-Chang Hsiao Yi-Syuan Li Chung-Hao Chen Hau-Chun Wu

A procedure has been developed for synthesis of 2-alkenyl-2H-indazoles starting from 2-(2-carbonylmethyl)-2H-indazoles, which are prepared by gallium/aluminium- and aluminium-mediated, direct, regioselective alkylation of indazoles with α-bromocarbonyl compounds. The structure of 3-(2H-indazol-2-yl)-2H-chromen-2-one was proven by X-ray crystallography. The styrene- and coumarin-2H-indazoles pro...

Journal: :Physical review research 2022

We report a detailed study of electrical and thermal transport properties in 2H-M$_x$TaS$_2$ (M = Mn, Co) magnets where M atoms are intercalated the van der Waals gap. The intercalation induces ferromagentism with an easy-plane anisotropy 2H-Mn$_x$TaS$_2$, but ferromagnetism strong uniaxial 2H-Co$_{0.22}$TaS$_2$, which finally evolves into three-dimensional antiferromagnetism 2H-Co$_{0.34}$TaS$...

2000
Michifumi Nagawa Musubu Ichikawa Toshiki Koyama Hirofusa Shirai Yoshio Taniguchi Akihito Hongo Shinji Tsuji Yoshiaki Nakano

We report an organic solid-state distributed feedback laser consisting of an organic active layer and a Bragg grating without morphological change. The active layer consists of 4-~dicyanomethylene!-2-methyl-6-~4-dimethylaminostryl!-4H-pyran as a laser dye, tris~8hydroxyquinoline! aluminum as a host, and poly~methyl methacrylate! as a binder. The threshold and linewidth of the laser are 400 mJ/c...

2014
Dongsoo Koh

In the structure of the title compound, C12H12O3, the di-hydro-pyran ring is fused with the benzene ring. The di-hydro-pyran ring is in a half-chair conformation, with the ring O and methyl-ene C atoms positioned 1.367 (3) and 1.504 (4) Å, respectively, on either side of the mean plane formed by the other four atoms. The meth-oxy group is coplanar with the benzene ring to which it is connected ...

2013
R. Vishnupriya J. Suresh S. Sivakumar R. Ranjith Kumar P. L. Nilantha Lakshman

In the title compound, C20H17N3O4, the central pyran ring adopts a boat conformation with the O atom and diagonally opposite C atoms displaced by 0.1171 (1) and 0.1791 (1) Å, respectively, from the mean plane defined by the other four atoms. The coplanar atoms of the pyran ring and the meth-oxy-benzene ring are nearly perpendicular, as evidenced by the dihedral angle 87.01 (1)°. The amine H ato...

2008
Jimmy J. P. Sejberg Jonathan Sperry Ka Wai Choi Peter D. W. Boyd Margaret A. Brimble

In the title compound, C(34)H(38)O(6), the methyl groups on each pyran ring exhibit 1,3-cis stereochemistry, established during synthesis by pseudo-axial delivery of hydride during a lactol reduction step. In the crystal structure, the mol-ecule lies on a twofold rotation axis and the torsion angle about the central diaryl bond is 41.3 (1)°. The mol-ecules pack in a herringbone arrangement.

2011
Marco A. Brito-Arias Miguel Soto-Ortega Efrén V. García-Báez

In the title compound, C(31)H(38)O(17), the 1,3-dioxane and pyran-oside rings both show (4)C(1) chair conformations while for the d-fructofuran-oside moiety an envelop 3E conformation is observed. The phenyl ring is oriented almost perpendicular to the 1,3-dioxane ring [dihedral angle = 79.3 (2)°], and the acetate groups are equatorial for the pyran-oside ring and axial for the furan-oside ring...

2012
Jae Kyun Lee Ae Nim Pae Yong Seo Cho Joo Hwan Cha

In the title compound, C(21)H(19)ClO(3), the two cyclo-hexenone rings adopt half-chair conformations, whereas the pyran ring adopts a boat conformation. The 4-chloro-phenyl ring is almost perpendicular to the plane through the four C atoms of the pyran ring [dihedral angle = 87.97 (6)°]. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules into a chain parallel to the a-axis.

Journal: :Chemical communications 2014
Gen Watanabe Ken Ohmori Keisuke Suzuki

A viable route has been developed for the selective synthesis of the 4→6-linked catechin dimers, scarcely accessible from Nature and/or through synthesis. An acyclic nucleophilic catechin precursor (seco-catechin) was used for the regioselective union with an electrophilic catechin unit, and subsequent pyran cyclization gave the desired 4→6-linked dimers, i.e., procyanidin B6 and catechin-(4α→6...

2008
Sung Myung SUNG MYUNG

The purpose of the present article is to show the multilinearity for symbols in Goodwillie-Lichtenbaum motivic complex in two cases. The first case shown is where the degree is equal to the weight. In this case, the motivic cohomology groups of a field are isomorphic to the Milnor’s K-groups as shown by Nesterenko-Suslin, Totaro and Suslin-Voevodsky for various motivic complexes, but we give an...

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