Synthesis and spatial structure of the geometrical isomers of 4-substituted 1-tert-butyl-3-methyl-piperidin-4-ols and 4-acyloxy-1-tert-butyl-3-methylpiperidines

1973 ◽  
Vol 9 (8) ◽  
pp. 979-983
Author(s):  
B. V. Unkovskii ◽  
Yu. F. Malina ◽  
T. D. Sokolova ◽  
S. I. Gavrilova ◽  
K. I. Romanova ◽  
...  
Keyword(s):  
Spatial Structure ◽  
Geometrical Isomers ◽  
Tert Butyl ◽  
Substituted 1

Article

1998 ◽  
Vol 76 (12) ◽  
pp. 1805-1816
Author(s):  
L Ross C Barclay ◽  
Jennifer K Grandy ◽  
Heather D MacKinnon ◽  
Heather C Nichol ◽  
Melinda R Vinqvist
Keyword(s):  
Oxygen Uptake ◽  
Singlet Oxygen ◽  
Sodium Azide ◽  
Lignin Content ◽  
Sodium Dodecyl ◽  
Kinetic Studies ◽  
Product Distribution ◽  
Geometrical Isomers ◽  
Photo Oxidation ◽  
Tert Butyl

3,5-Di-tert-butyl-ortho-quinone, 6, and 1-(3,4-dimethoxyphenyl-2-(2-methoxyphenoxy)-1-propanone, 7, models for oxidized lignin and for lignin, were used as sensitizers of photo-oxidation. Product studies by HPLC from oxidation of methyl linoleate in solution sensitized by 6 or 7, and in sodium dodecyl sulfate (SDS) sensitized by 6, showed a product distribution of six hydroperoxides, the four conjugated 9- and 13-hydroperoxides of the geometrical isomers: trans-10, cis-12 (2), cis-9, trans-11 (3), trans-10, trans-12 (4), and trans-9, trans-11 (5)-octadecadienoates plus two nonconjugated hydroperoxides. The higher cis/trans to trans/trans (ct/tt) of geometrical isomers (2 + 3//4 + 5) compared to ct/tt from known thermal free-radical peroxidations (Type 1) indicate that singlet oxygen (Type 2) oxidation occurs in reactions sensitized by 6 or 7. Kinetic studies by oxygen uptake are reported on oxidations of hydrocarbons 1-phenyl-2-methylpropene,8, and trans-stilbene,9, sensitized by the quinone, 6, or by a dye, Rose Bengal. Quenching studies imply singlet oxygen reactions. Milled wood lignin undergoes self-initiated photo-oxidation in water, and oxygen uptake was quenched by sodium azide. Cellobiose, a cellulose model, undergoes sensitized photo-oxidation using model quinone, 6, in a mixture of tert-butyl alcohol and water or using the sensitizers benzophenone or the lignin model, 7, delivered on a solid support, silica gel, and these oxidations were quenched with sodium azide. These results implicate singlet oxygen in the photo-yellowing of high lignin content wood pulps.Key words: lignin models, ortho-quinone, photo-oxidation, singlet oxygen, lignin, cellobiose.

ChemInform Abstract: SYNTHESIS OF GEOMETRIC ISOMERS OF SOME 4-MONO-SUBSTITUTED 1-TERT-BUTYL-3-METHYLPIPERIDINES

1976 ◽  
Vol 7 (34) ◽  
pp. no-no
Author(s):  
K. I. ROMANOVA ◽  
T. D. SOKOLOVA ◽  
YU. F. MALINA ◽  
B. V. UNKOVSKII
Keyword(s):  
Geometric Isomers ◽  
Tert Butyl ◽  
Substituted 1

Darstellung und Thermolyse tert-butylsubstituierter Silatetrazoline – Erzeugung der Silanimine tBu2Si=N-SiXtBu2 (X = F, Cl, Br, tBu) Synthesis and Thermolysis of the tert-Butyl-Substituted Silatetrazolines – Formation of the Silanimines tBu2Si=N-SiXtBu2 (X = F, Cl, Br, tBu)

2002 ◽  
Vol 57 (11) ◽  
pp. 1199-1206 ◽  
Author(s):  
Hans-Wolfram Lerner ◽  
Nils Wiberg ◽  
K. Polborn
Keyword(s):  
Structure Analysis ◽  
Order Process ◽  
X Ray ◽  
First Order ◽  
Tert Butyl ◽  
Substituted 1

The silanimine tBu2Si=N-SitBu3 reacts with the silyl azides tBuMe2SiN3 or tBu2SiXN3 (X = H, Me, F, Cl, Br) to form the corresponding tert-butyl-substituted 1-tri-tert-butylsilyl-4-triorganosilyl- 5,5-di-tert-butylsilatetrazolines. The silatetrazolines with chloro-di-tert-butylsilyl and bromo-di-tert-butylsilyl substituents can also be synthesized by treating two equivalents of tBu2SiXN3 (X = Cl, Br) with the silanide tBu3SiNa. In the thermolysis of the silaterazolines the silanimines tBu2Si=N-SiXtBu2 (X = F, Cl, Br, tBu) and silyl azides are formed in a first-order process. The silanimines tBu2Si=N-SiXtBu2 (X= F, Cl, Br, tBu) have been trapped with acetone by en-reaction. The structure of (dimethyl-tert-butylsilyl)-substituted silatetrazoline has been determined by X-ray structure analysis.

SPATIAL STRUCTURE OF MONO AND BIS AMIDE-SUBSTITUTED p-TERT-BUTYL-THIACALIX[4]ARENES IN THE CRYSTAL PHASE

2021 ◽  
Vol 62 (9) ◽  
pp. 1432-1440
Author(s):  
I. A. Litvinov ◽  
D. A. Islamov ◽  
O. A. Ovsyannikov ◽  
S. E. Solovieva
Keyword(s):  
Spatial Structure ◽  
Crystal Phase ◽  
Tert Butyl
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