PRESSURE EFFECT AND MECHANISM IN ACID CATALYSIS XIII. HYDROLYSIS OF METHYL α-D-GLUCOPYRANOSIDE

1963 ◽  
Vol 41 (7) ◽  
pp. 1849-1850 ◽  
Author(s):  
R. J. Withey ◽  
E. Whalley
Keyword(s):  
Acid Catalysis ◽  
Pressure Effect ◽  
Hydrolysis Of

not available

PRESSURE EFFECT AND MECHANISM IN ACID CATALYSIS: VIII. HYDROLYSIS OF ACETAMIDE AND BENZAMIDE

1961 ◽  
Vol 39 (5) ◽  
pp. 1101-1108 ◽  
Author(s):  
A. R. Osborn ◽  
T. C-W. Mak ◽  
E. Whalley
Keyword(s):  
Water Molecule ◽  
Transition State ◽  
Perchloric Acid ◽  
Acid Catalysis ◽  
Pressure Effect ◽  
Protonated Form ◽  
Dilute Acid ◽  
Additional Information ◽  
Acid Catalyzed ◽  
Hydrolysis Of

The effect of pressures up to 3 kbar on the rate of the acid-catalyzed hydrolysis of acetamide and benzamide in both dilute and concentrated perchloric acid has been measured. The volumes of activation in dilute acid are consistent with a transition state that is not highly polar. It follows from this that if the attacking water molecule adds to the amidium ion then the reactive amidium ion is the O-protonated form, and if the attacking water molecule substitutes then the reactive amidium ion is the N-protonated form.The volume of activation for acetamide in concentrated acid provides no additional information about the mechanism. That for benzamide in concentrated acid is tentatively interpreted as favoring the O-protonated benzamidium ion as the reactive ion.

PRESSURE EFFECT AND MECHANISM IN ACID CATALYSIS: IV. THE HYDROLYSIS OF DIETHYL ETHER

1959 ◽  
Vol 37 (4) ◽  
pp. 788-794 ◽  
Author(s):  
J. Koskikallio ◽  
E. Whalley
Keyword(s):  
Diethyl Ether ◽  
Acid Catalysis ◽  
Pressure Effect ◽  
Slow Step ◽  
Acidity Function ◽  
Temperature Range ◽  
Entropy Of Activation ◽  
Acid Catalyzed ◽  
Hydrolysis Of

The acid-catalyzed hydrolysis of diethyl ether has been measured in the temperature range 120–160 °C at low acid concentrations; the entropy of activation is −9.0 ± ~2.5 cal deg−1 mole−1. The effect of pressures up to 3000 atm has been measured at 161.2 °C; the volume of activation at 1 atm is −8.5 ± ~2 cm3 mole−1. These two results show that the slow step is bimolecular. The rate in concentrated acids was measured at 119 °C; the rate was much more nearly proportional to the acidity function h0 than to concentration of acid. This is contrary to the predictions of the Zucker–Hammett hypothesis, which is therefore not valid for the hydrolysis of diethyl ether.

PRESSURE EFFECT AND MECHANISM IN ACID CATALYSIS: VI. HYDROLYSIS OF α-D-GLUCOSE-1-PHOSPHATE

1961 ◽  
Vol 39 (3) ◽  
pp. 597-599 ◽  
Author(s):  
A. R. Osborn ◽  
E. Whalley
Keyword(s):  
Acid Catalysis ◽  
Pressure Effect ◽  
Hydrolysis Of

not available

PRESSURE EFFECT AND MECHANISM IN ACID CATALYSIS: V. THE HYDROLYSIS OF ACETIC ANHYDRIDE

1959 ◽  
Vol 37 (8) ◽  
pp. 1360-1366 ◽  
Author(s):  
J. Koskikallio ◽  
D. Pouli ◽  
E. Whalley
Keyword(s):  
Acetic Anhydride ◽  
Acid Catalysis ◽  
Pressure Effect ◽  
Valid Method ◽  
Acetone Water ◽  
Entropy Of Activation ◽  
Acid Catalyzed ◽  
Hydrolysis Of

The spontaneous and the acid-catalyzed hydrolyses of acetic anhydride have been measured as a function of temperature over the range 0 to 40 °C, as a function of pressure over the range 0 to 3 kb at 0 °C, and as a function of solvent over the range 0 to 70.3% w/w acetone–water at 0 °C. The results are discussed with reference to the mechanisms of the hydrolyses. The volume and entropy of activation of the acid-catalyzed hydrolysis are −17.1 ± ~1.3 cm3 mole−1 and ~ −20 cal deg−1 mole−1, showing that the mechanism[Formula: see text]suggested because the rate was proportional to Hammett's h0, is not correct. It follows that the Zucker–Hammett hypothesis is invalid for this reaction, as we have shown previously for other reactions, and hence that it does not provide a valid method of distinguishing between the A-1 and A-2 mechanisms.

Nonenzymatic Hydrolysis of Cocainevia Intramolecular Acid Catalysis

1999 ◽  
Vol 82 (1) ◽  
pp. 85-89 ◽  
Author(s):  
Pan Li ◽  
Kang Zhao ◽  
Shixian Deng ◽  
Donald W. Landry
Keyword(s):  
Acid Catalysis ◽  
Hydrolysis Of
Sign in / Sign up

Export Citation Format

Share Document