scholarly journals Contra-Thermodynamic Positional Isomerization of Olefins

2021 ◽  
Author(s):  
Kuo Zhao ◽  
Robert R. Knowles
Keyword(s):  
Positional Isomerization

Discovery and Insight into One-photon and Two-photon Excited ACQ-to-AIE Conversion via Positional Isomerization

2021 ◽  
Author(s):  
Xueting Long ◽  
Jieyu Wu ◽  
Sirui Yang ◽  
Ziqi Deng ◽  
Yusen Zheng ◽  
...  
Keyword(s):  
Positional Isomers ◽  
Two Photon ◽  
Positional Isomerization ◽  
Aggregation Behaviors ◽  
Insight Into

Two positional isomers (regioisomers) through changing the substituted position of perylenetetracarboxylic diimide and benzanthrone moieties were designed and synthesized. These two regioisomers exhibit totally different aggregation behaviors. The meta (bay)-substituted...

scholarly journals An improved procedure for the preparation of alkyl sulphate esters suitable for the study of secondary alkylsulphohydrolase enzymes

1980 ◽  
Vol 187 (1) ◽  
pp. 191-196 ◽  
Author(s):  
G F White ◽  
V Lillis ◽  
D J Shaw
Keyword(s):  
Hydroxy Group ◽  
Convenient Method ◽  
Carbon Chain ◽  
Alkyl Sulphate ◽  
Positional Isomerization ◽  
Sodium Alkoxide ◽  
Long Chain

A simple, rapid and convenient method for the synthesis of secondary alkyl sulphate esters is described in which the sodium alkoxide of the parent alcohol is sulphated by using triethylamine-SO3 complex. The procedure gives relatively good yields, even for the sulphation of long-chain alcohols and those in which the hydroxy group is remote from the terminal carbon atoms. Positional isomerization, arising from the migration of the hydroxy group along the carbon chain, is absent, and resolved enantiomers of alcohols react with complete retention of configuration.

scholarly journals Positional Isomerization of Phenylethanoid Glycosides from Magnolia officinalis

2016 ◽  
Vol 11 (12) ◽  
pp. 1934578X1601101 ◽  
Author(s):  
Zhenzhen Xue ◽  
Hua Li ◽  
Bin Yang
Keyword(s):  
Exposure Time ◽  
Critical Role ◽  
Phenylethanoid Glycosides ◽  
Positional Isomerization ◽  
Solvent Type ◽  
Magnolia Officinalis ◽  
Final Purification

Positional isomerization, an inducement leading to instability of phenylethanoid glycosides (PhGs) containing the caffeoyl moiety linked to C-3/4 of the central saccharide, is reported. Magnolosides M, A and F from Magnolia officinalis were found to be transformed into their isomers magnolosides A, D, M and B, respectively, which indicated that PhGs containing the caffeoyl moiety linking to C-3/4 of the central saccharide were unstable, and the caffeoyl group could be transferred to either C-4/3 or C-6 of the central saccharide. In addition, among the factors of temperature, solvent type and exposure time in solvent, temperature was found to play a critical role in initiation of positional isomerization of PhGs. In order to retard this isomerization, the temperature should be lower than 40°C during the final purification stages of PhGs.

The process of producing 2-methyl-2-butene by positional isomerization on sulfocation exchangers

2009 ◽  
Vol 82 (6) ◽  
pp. 1128-1132
Author(s):  
O. S. Pavlov ◽  
S. A. Karsakov ◽  
S. Yu. Pavlov
Keyword(s):  
Positional Isomerization
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