Kinetics and mechanism of the acid-catalyzed hydrolysis of 1,1-dimethoxyethene (ketene dimethyl acetal) and trimethoxyethene in aqueous solution

1992 ◽  
Vol 114 (8) ◽  
pp. 3099-3102 ◽  
Author(s):  
A. J. Kresge ◽  
M. Leibovitch
Keyword(s):  
Aqueous Solution ◽  
Dimethyl Acetal ◽  
Kinetics And Mechanism ◽  
Acid Catalyzed ◽  
Hydrolysis Of

Acid-catalyzed hydrolysis of tetramethoxyethene in aqueous solution. Initial state stabilization by the methoxy groups

1990 ◽  
Vol 68 (10) ◽  
pp. 1786-1790 ◽  
Author(s):  
A. J. Kresge ◽  
M. Leibovitch ◽  
K. R. Kopecky
Keyword(s):  
Aqueous Solution ◽  
Dimethyl Acetal ◽  
Initial State ◽  
Olefinic Carbon ◽  
Hydronium Ion ◽  
Methoxy Groups ◽  
Rate Retardation ◽  
Acid Catalyzed ◽  
Solvent Isotope ◽  
Hydrolysis Of

The acid-catalyzed hydrolysis of tetramethoxyethene to methyl dimethoxyacetate in aqueous solution at 25 °C was found to occur with the hydronium-ion catalytic coefficient [Formula: see text], to give the solvent isotope effect [Formula: see text], and to provide a Brønsted relation based upon six carboxylic acids with the exponent α = 0.42. These data indicate that the reaction proceeds via rate-determining proton transfer from the catalyzing acid to an olefinic carbon atom of the substrate. They also show tetramethoxyethene to be 1.0 × 106 times less reactive than 1,1-dimethoxyethene (ketene dimethyl acetal), a rate retardation 600 times greater than that expected from initial state stabilization by the two additional methoxy groups in tetramethoxyethene; possible causes of this disparity are discussed. Keywords: tetramethoxyethene, carbon–carbon double bond reactivity, ketene acetal, vinyl ether hydrolysis.

THE CHEMISTRY OF ETHYLENE OXIDE: V. THE REACTION OF ETHYLENE OXIDE WITH HALIDE IONS IN NEUTRAL AND ACID SOLUTION

1952 ◽  
Vol 30 (3) ◽  
pp. 169-176 ◽  
Author(s):  
A. M. Eastham ◽  
G. A. Latremouille
Keyword(s):  
Aqueous Solution ◽  
Ethylene Oxide ◽  
Acid Solution ◽  
Activation Energies ◽  
Hydrogen Halide ◽  
Halide Ions ◽  
Neutral Aqueous Solution ◽  
Rate Of Hydrolysis ◽  
Acid Catalyzed ◽  
Hydrolysis Of

The rates of reaction of halide ions with ethylene oxide in neutral aqueous solution and the rate of hydrolysis of ethylene oxide in acid solution have been measured and the activation energies determined. From these data and from the ratio of glycol to chlorohydrin formed when ethylene oxide reacts with excess aqueous hydrogen halide, the rates of the acid-catalyzed addition of halide ions to ethylene oxide at 25 °C. have been estimated.

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