Acid-catalyzed hydrolysis of cis- and trans-1,2-dimethoxyethene in aqueous solution

1990 ◽  
Vol 55 (18) ◽  
pp. 5234-5236 ◽  
Author(s):  
A. J. Kresge ◽  
M. Leibovitch
Keyword(s):  
Aqueous Solution ◽  
Acid Catalyzed ◽  
Cis And Trans ◽  
Hydrolysis Of

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.

Acid-catalyzed hydrolysis of 2-methylene-1,3-dithiolane. 2. Remarkable effects of β substitution on reversibility of the carbon protonation

1986 ◽  
Vol 64 (6) ◽  
pp. 1116-1123 ◽  
Author(s):  
Tadashi Okuyama ◽  
Masayoshi Toyoda ◽  
Takayuki Fueno
Keyword(s):  
Aqueous Solution ◽  
Rate Constants ◽  
Isotope Exchange ◽  
Relative Stabilities ◽  
The Third ◽  
Initial Carbon ◽  
Acid Catalyzed ◽  
The Individual ◽  
Individual Rate ◽  
Hydrolysis Of

Hydrolyses of 2-ethylidene-(1b), 2-isopropylidene-(1c), and 2-benzylidene-1,3-dithiolane (1d) were kinetically investigated in aqueous solution. All the individual rate constants involved in this three-step reaction were evaluated. Initial carbon protonation is only partially reversible (k2/k−1 = 1.33, 0.68, and 1.02 for 1b, 1c, and 1d, respectively) at higher pH, while the protonation becomes completely reversible below pH 2 where the third step is rate determining. Complete H–D isotope exchange at the β-carbon of 1b and 1d was observed in deuterium media before appreciable hydrolysis took place. It was demonstrated that reversion from the tetrahedral intermediate 3 to 1 occurs extensively during the reaction in the latter acidity range. Relative stabilities and reactivities of the olefinic substrates 1 are discussed.

Cis- and trans-2,4-dimethoxytetrahydropyran. Models for the study of the anomeric effect

1968 ◽  
Vol 46 (9) ◽  
pp. 1543-1548 ◽  
Author(s):  
F. Sweet ◽  
R. K. Brown
Keyword(s):  
Good Yield ◽  
Methoxy Group ◽  
Equilibrium Mixture ◽  
Anomeric Effect ◽  
Kcal Mole ◽  
Mild Acid Hydrolysis ◽  
Acid Catalyzed ◽  
Cis And Trans ◽  
Hydrolysis Of ◽  
Mild Acid

Acid-catalyzed methanolysis of 2-methoxy-5,6-dihydro-2H-pyran gave, in good yield, a 4.0:1.0 mixture of trans- and cis-2,4-dimethoxytetrahydropyran. Mild acid hydrolysis of 2-methoxy-5,6-dihydro-2H-pyran followed by acid-catalyzed reaction with methanol gave a cis-trans mixture of 4-hydroxy-2-methoxytetrahydropyran in very poor yield.From the equilibrium mixture of trans- and cis-2,4-dimethoxytetrahydropyran (4.0:1.0), the magnitude of the anomeric effect of the 2-methoxy group was calculated to be 1.4 kcal/mole.

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