Results 51 to 60 of about 19,944 (197)

Research Progress on the Selectivity and Biomagnification of Chiral Hexabromocyclododecanes Pollutants in Food Chain Transfer

Yankuang ceshi, 2016
Hexabromocyclododecanes (HBCDs) are globally produced brominated flame retardant (BFR) and are used primarily as an additive FR in thermal insulation building materials, upholstery textiles, and electronics.
TIAN Qin, TONG Ling, SONG Shu-ling, ZHAN Nan, PAN Meng, QIU Jing   +5 more
doaj   +1 more source

Intramolecular Hydrogen Bonding in α-Epoxy Alcohols: A Conformational Analysis of 1,2-Dialkyl-2,3-epoxycyclopentanol Diastereomers

, 2018
Geometry optimizations for 11 1,2-disubstituted-2,3-epoxycyclopentanol diastereomers were studied using the M06-2X/cc-pVTZ method and basis set to probe mechanistic details in the α-epoxy alcohol semipinacol rearrangement reaction. Electronic energies of
Justin W. Weeks, Gregory S. Tschumper, Yasmeen A. Abdo, Joshua W. Graham, Mikayla E. Tabor, Layfield, William, Tabor, Mikayla E., Carr, Jeremy M., William Layfield, Sarah E. Causey, Weeks, Justin W., Causey, Sarah E., William M. Tremlett, Abdo, Yasmeen A., Tremlett, William M., Jeremy M. Carr, Graham, Joshua W., Tschumper, Gregory S.   +17 more
core   +1 more source

Double Intramolecular Transacetalization of Polyhydroxy Acetals: Synthesis of Conformationally-Restricted 1,3-Dioxanes with Axially-Oriented Phenyl Moiety

Molecules, 2016
The synthesis of conformationally-restricted 1,3-dioxanes with a phenyl moiety fixed in an axial orientation at the acetalic center is described. Starting with diethyl 3-hydroxyglutarate (15), benzaldehyde acetal 12a and acetophenone ketal 12b bearing a ...
Samuel Asare-Nkansah, Bernhard Wünsch
doaj   +1 more source

Separation of folinic acid diastereomers in capillary electrophoresis using a new cationic β-cyclodextrin derivative. [PDF]

PLoS ONE, 2015
A method for the separation of folinic acid diastereomers by capillary electrophoresis in chiral separation media was developed. Aiming to achieve a good separation of the anionic analytes, a newly synthesized cationic β-cyclodextrin derivative, mono-6 ...
Jia Yu, Xinlei Liang, Zhaokun Wang, Xin Guo, Tiemin Sun, Xingjie Guo   +5 more
doaj   +1 more source

Conformation and Permeability: Cyclic Hexapeptide Diastereomers

Journal of Chemical Information and Modeling, 2019
Conformational ensembles of eight cyclic hexapeptide diastereomers in explicit cyclohexane, chloroform, and water were analyzed by multicanonical molecular dynamics (McMD) simulations. Free-energy landscapes (FELs) for each compound and solvent were obtained from the molecular shapes and principal component analysis at T = 300 K; detailed analysis of ...
Satoshi Ono, Matthew R. Naylor, Chad E. Townsend, Chieko Okumura, Okimasa Okada, R. Scott Lokey   +5 more
openaire   +3 more sources

Reversed-phase HPLC separation of the diastereomers of compound 1.

, 2014
Panel A: chromatogram of the racemic mix of the diastereomers of compound 1 analyzed by reversed-phase HPLC using a XBridge C18 column, 3.5 µm, 4.6×150 mm (Waters Inc., Waltham, Mass.
Alan D. Michelson (344645), Milka Yanachkova (550364), Hung Chang (550361), George E. Wright (550366), Ivan B. Yanachkov (550362), YouFu Li (550365), Marc R. Barnard (344651), Edward J. Dix (550363), Andrew L. Frelinger III (344646)   +8 more
core   +1 more source

The Effect of Alkyl Substituents on the Formation and Structure of Homochiral (R*,R*)-[R₂Ga(µ-OCH(Me)CO₂R′)]₂ Species—Towards the Factors Controlling the Stereoselectivity of Dialkylgallium Alkoxides in the Ring-Opening Polymerization of rac-Lactide

Molecules
Building on our previous studies, which have demonstrated that homochiral propagating species—(R*,R*)-[Me2Ga(µ-OCH(Me)CO2R)]2—were crucial for the heteroselectivity of [Me2Ga(µ-OCH(Me)CO2Me)]2 in the ring-opening polymerization (ROP) of racemic lactide ...
Magdalena Kaźmierczak, Łukasz Dobrzycki, Maciej Dranka, Paweł Horeglad   +3 more
doaj   +1 more source

diastereomers

, 2010
Citation: 'diastereomers' in the IUPAC Compendium of Chemical Terminology, 3rd ed.; International Union of Pure and Applied Chemistry; 2006. Online version 3.0.1, 2019. 10.1351/goldbook.D01682 • License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International for individual terms. Requests for commercial
openaire   +1 more source

Synthesis of four diastereomers and structural revision of tetradenolide

, 2014
Four diastereomers of tetradenolide, a cytotoxic α-pyrone isolated from Tetradenia riparia, were synthesized stereoselectively using the Z-selective Horner–Emmons reaction followed by acid catalyzed lactonization.
Makabe, Hidefumi, Tokuda, Maki, Nohara, Yukie, Tokuda, Maki, Kurogome, Yuji, Katoh, Rieko, Makabe, Hidefumi, Kurogome, Yuji, Nohara, Yukie, Hattori, Yasunao, Hattori, Yasunao, Katoh, Rieko   +11 more
core   +1 more source

Diastereoselective Spiroannulation of Phenolic Substrates: Advances Towards the Asymmetric Formation of the Manumycin m-C7N Core Skeleton

Molecules, 2007
The asymmetric syntheses of two new spirolactones prepared in optically pure form from L-3-nitrotyrosine are described. The key step, an oxidative spiroannulation, was carried out on the optically active phenols 11a and 11b and afforded the new ...
Thomas W. Scully, Jolene S. Kwasnitza, Randy R. Spaetzel, Guy L. Plourde   +3 more
doaj   +1 more source