Arrhenius parameters for the alkaline hydrolysis of glycine ethyl ester, in aqueous solution, and thermodynamic functions for its ionisation as an acid

1967 ◽  
pp. 1265 ◽  
Author(s):  
Margaret Robson Wright
Keyword(s):  
Aqueous Solution ◽  
Ethyl Ester ◽  
Thermodynamic Functions ◽  
Alkaline Hydrolysis ◽  
Arrhenius Parameters ◽  
Glycine Ethyl Ester ◽  
Hydrolysis Of

Synthesis of Normuramic Acid Carba Analog and Its Glycopeptide Derivative Resistant to β-Elimination Splitting of the Side Chain

2000 ◽  
Vol 65 (11) ◽  
pp. 1726-1736 ◽  
Author(s):  
Miroslav Ledvina ◽  
Radka Pavelová ◽  
Anna Rohlenová ◽  
Jan Ježek ◽  
David Šaman
Keyword(s):  
Ethyl Ester ◽  
Alkaline Hydrolysis ◽  
Benzyl Ester ◽  
Side Chain ◽  
Propanoic Acid ◽  
Hydrolysis Of

Carba analogs of normuramic acid, i.e., 3-(benzyl 2-acetamido-2,3-dideoxy-4,6-O-isopropylidene-α-D-glucopyranosid-3-yl)propanoic acid derivatives (nitrile or esters) 3a-3c were prepared by addition of radicals generated from benzyl 2-acetamido-2-deoxy-4,6-O-isopropylidene-3-O-[(methylsulfanyl)thiocarbonyl]- (2a) or -3-O-(phenoxythiocarbonyl)-α-D-glucopyranoside (2b) with Bu3SnH to acrylonitrile or acryl esters. Alkaline hydrolysis of ethyl ester 3c afforded 3-(benzyl 2-acetamido-2,3-dideoxy-4,6-O-isopropylidene-α-D-glucopyranosid-3-yl)propanoic acid (5). Coupling of acid 5 with L-2-aminobutanoyl-D-isoglutamine benzyl ester trifluoroacetate and subsequent deprotection of the intermediate 6 furnished N-[3-(2-acetamido-2,3-dideoxy-α-D-glucopyranosid-3-yl)propanoyl]-L-2-aminobutanoyl-D-isoglutamine (7).

The Chemical Evolution of a Nitrogenase Model, 20 Alkyl Molybdates(VI) and the Mechanism of Hydrocarbon Production by Nitrogenase [1]

1982 ◽  
Vol 37 (3) ◽  
pp. 380-385 ◽  
Author(s):  
G. N. Schrauzer ◽  
Laura A. Hughes ◽  
Norman Strampach
Keyword(s):  
Aqueous Solution ◽  
Alkaline Hydrolysis ◽  
Room Temperature ◽  
Bond Cleavage ◽  
Model Compounds ◽  
Hydrocarbon Production ◽  
Acidic Solutions ◽  
Reducing Conditions ◽  
Hydrolysis Of ◽  
Derivatives Of

Abstract Colorless alkylmolybdates(VI) of composition R-MoO3-are generated in aqueous solutions by the alkaline hydrolysis of complexes R-Mo(Bpy)(0)2Br(Bpy = 2,2′-bipyridyl, R = CH3 and higher alkyl). At room temperature in alkaline aqueous solution, the new organometallic derivatives of oxomolybdate(VI) are remarkably resistant against Mo-C bond hydrolysis. Decomposition occurs more rapidly on heating, affording unrearranged alkanes according to the eq.: R-MoO3- + OH-→RH + Mo04=. In acidic solutions, the methylmolybdate(VI) species decomposes with the formation of a mixture of methane and ethane while higher alkylmolybdates carrying hydrogen in the β-position relative to molybdenum undergo Mo-C bond heterolysis by way of β-elimina-tion: R-CH2CH2-MoO3 → Mo+4 (aq) + H+ + R-CH = CH2. The Mo-C bond of alkylmolybdates is resistant to oxidants but is very sensitive to cleavage under reducing conditions. Reductive Mo-C bond cleavage occurs particularly rapidly in the presence of thiols and reduced ferredoxin model compounds. The latter reactions simulate the terminal steps of hydrocarbon producing reactions of nitrogenase with alternate substrates such as CN-, R-CN or R-NC, confirming previous mechanistic conclusions concerning the mechanism of nitrogenase action.

The acid-catalysed hydrolysis of α-methylallyl acetate in aqueous solution

1968 ◽  
Vol 21 (7) ◽  
pp. 1727
Author(s):  
RA Fredlein ◽  
I Lauder
Keyword(s):  
Aqueous Solution ◽  
Reaction Products ◽  
Arrhenius Parameters ◽  
Crotyl Alcohol ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Tracer Experiments

The kinetics of the acid-catalysed hydrolysis of a-methylallyl acetate in aqueous solution have been studied over the range 30-100�. Oxygen-18 tracer experiments reveal the mechanism to be solely Aac2 and the Arrhenius parameters are consistent with this conclusion. Crotyl alcohol is observed in the reaction products. The formation of rearranged alcohol is explained by allylic isomerization of the α-methylallyl alcohol produced by the hydrolysis.

scholarly journals MICELLAR CATALYZED REACTION IN AQUEOUS GLYCEROL SOLUTIONS AND THE INTERNAL PRESSURE OF THE MEDIUM

2008 ◽  
Vol 16 (16) ◽  
pp. 41-57
Author(s):  
Lavinel G. IONESCU ◽  
Vera Lucia Trindade ◽  
Elizabeth Fatima de Souza
Keyword(s):  
Aqueous Solution ◽  
Internal Pressure ◽  
Sodium Hydroxide ◽  
Alkaline Hydrolysis ◽  
Cetyltrimethylammonium Bromide ◽  
Reaction Medium ◽  
Phosphate Ester ◽  
Cohesive Forces ◽  
Diphenyl Phosphate ◽  
Hydrolysis Of

The experimental results obtained/or the hydrolysis of p-nitrophenyl diphenyl phosphate (NPDPP) in the presence of sodium hydroxide (NaOH), micelles of cetyltrimethylammonium bromide (CTAB), and an aqueous solution of glycerol were analyzed taking into consideration the internal pressure and the cohesive forces of the reaction medium. The effect of glycerol on mice/le formation and also its influence on the internal pressure of the reaction medium are large enough to affect the micellar catalyzed alkaline hydrolysis of the phosphate ester.

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