Studies on Thioesters Related to Coenzyme A. A Kinetic Study of Aminolysis and Hydrolysis of β-(N-Methylacetamino)-ethyl Thioacetate, N,S-Diacetylaletheine and γ-Acetaminopropyl Thioacetate1

1956 ◽  
Vol 78 (12) ◽  
pp. 2731-2735 ◽  
Author(s):  
D. Stanley Tarbell ◽  
Donald P. Cameron
Keyword(s):  
Kinetic Study ◽  
Coenzyme A ◽  
Hydrolysis Of

Benzyl ethers of methyl α-D-glucopyranoside

1980 ◽  
Vol 45 (7) ◽  
pp. 1959-1963 ◽  
Author(s):  
Dušan Joniak ◽  
Božena Košíková ◽  
Ludmila Kosáková
Keyword(s):  
Kinetic Study ◽  
Spectrophotometric Determination ◽  
Reductive Cleavage ◽  
Ether Bond ◽  
Benzyl Ethers ◽  
Acid Catalyzed ◽  
Model Substances ◽  
Hydrolysis Of

Methyl 4-O-(3-methoxy-4-hydroxybenzyl) and methyl 4-O-(3,5-dimethoxy-4-hydroxybenzyl)-α-D-glucopyranoside and their 6-O-isomers were prepared as model substances for the ether lignin-saccharide bond by reductive cleavage of corresponding 4,6-O-benzylidene derivatives. Kinetic study of acid-catalyzed hydrolysis of the compounds prepared was carried out by spectrophotometric determination of the benzyl alcoholic groups set free, after their reaction with quinonemonochloroimide, and it showed the low stability of the p-hydroxybenzyl ether bond.

Kinetic Study of Hydrolysis of Benzoates. Part XXVI. Variation of the Substituent Effect with Solvent in Alkaline Hydrolysis of Substituted Alkyl Benzoates

2006 ◽  
Vol 71 (11-12) ◽  
pp. 1557-1570 ◽  
Author(s):  
Vilve Nummert ◽  
Mare Piirsalu ◽  
Ilmar A. Koppel
Keyword(s):  
Kinetic Study ◽  
Alkaline Hydrolysis ◽  
Rate Constants ◽  
Substituent Effect ◽  
Substituent Effects ◽  
Alkyl Substituent ◽  
Solvent Parameters ◽  
Substituent Constants ◽  
Hydrolysis Of ◽  
Main Factor

The second-order rate constants k2 (dm3 mol-1 s-1) for the alkaline hydrolysis of substituted alkyl benzoates C6H5CO2R have been measured spectrophotometrically in aqueous 0.5 M Bu4NBr at 50 and 25 °C (R = CH3, CH2Cl, CH2CN, CH2C≡CH, CH2C6H5, CH2CH2Cl, CH2CH2OCH3, CH2CH3) and in aqueous 5.3 M NaClO4 at 25 °C (R = CH3, CH2Cl, CH2CN, CH2C≡CH). The dependence of the alkyl substituent effects on different solvent parameters was studied using the following equations:      ∆ log k = c0 + c1σI + c2EsB + c3∆E + c4∆Y + c5∆P + c6∆EσI + c7∆YσI + c8∆PσI     ∆ log k = c0 + c1σ* + c2EsB + c3∆E + c4∆Y + c5∆P + c6∆Eσ* + c7∆Yσ* + c8∆Pσ* .  ∆ log k = log kR - log kCH3. σI and σ* are the Taft inductive and polar substituent constants. E, Y and P are the solvent electrophilicity, polarity and polarizability parameters, respectively. In the data treatment ∆E = ES - EH2O , ∆Y = YS - YH2O , ∆P = PS - PH2O were used. The solvent electrophilicity, E, was found to be the main factor responsible for changes in alkyl substituent effects with medium. When σI constants were used, variation of the polar term of alkyl substituents with the solvent electrophilicity E was found to be similar to that observed earlier for meta and para substituents, but twice less when σ* constants were used. The steric term for alkyl substituents was approximately independent of the solvent parameters.

A Kinetic Study of the Copper(II) Chelate Catalyzed Hydrolysis of Diisopropyl Phosphorofluoridate

1963 ◽  
Vol 85 (5) ◽  
pp. 598-601 ◽  
Author(s):  
Richard L. Gustafson ◽  
Stanley. Chaberek ◽  
Arthur E. Martell
Keyword(s):  
Kinetic Study ◽  
Diisopropyl Phosphorofluoridate ◽  
Hydrolysis Of

ChemInform Abstract: A KINETIC STUDY ON THE HYDROLYSIS OF METHYL 2-TRIMETHYLSILOXYBENZOATE

1974 ◽  
Vol 5 (39) ◽  
pp. no-no
Author(s):  
ALEKSANDER RADECKI ◽  
HENRYK LAMPARCZYK ◽  
JAN HALKIEWICZ ◽  
ZYGMUNT JAMROGIEWICZ
Keyword(s):  
Kinetic Study ◽  
Hydrolysis Of

A kinetic study of the acid autoxidation of tryptophan

1972 ◽  
Vol 25 (10) ◽  
pp. 2139 ◽  
Author(s):  
M Stewart ◽  
CH Nicholls
Keyword(s):  
Free Radical ◽  
Amino Acid ◽  
Kinetic Study ◽  
Acid Hydrolysis ◽  
Soda Glass ◽  
Glass Containers ◽  
Hydrolysis Of

The decomposition of tryptophan in aqueous HC1 at 100�C has been shown to proceed by a free-radical autoxidation mechanism. The acid functions by protonating the amino acid at either the 1- or 3-positions prior to autoxidation and so 1-methyltryptophan is also decomposed under these conditions. Impurities present in the soda glass containers used are shown to be responsible for the initiation of the reaction. The decomposition of tryptophan during the acid hydrolysis of proteins is considered in the light of these results.

A kinetic study of the hydrolysis of 2-germaacetate in neutral and alkaline solutions

1977 ◽  
Vol 16 (11) ◽  
pp. 2834-2837 ◽  
Author(s):  
Duck J. Yang ◽  
William L. Jolly
Keyword(s):  
Kinetic Study ◽  
Alkaline Solutions ◽  
Hydrolysis Of

Kinetic study of the acid-promoted hydrolysis of some representative 2-fluoronitrogen heterocycles

1981 ◽  
Vol 46 (22) ◽  
pp. 4363-4369 ◽  
Author(s):  
H. R. Clark ◽  
L. D. Beth ◽  
R. M. Burton ◽  
D. L. Garrett ◽  
A. L. Miller ◽  
...  
Keyword(s):  
Kinetic Study ◽  
Hydrolysis Of
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