Alkali hydrolysis of diethyl malonates: Theoretical conformation analysis for substrates and tetrahedral intermediates

1991 ◽  
Vol 26 (6) ◽  
pp. 633-638
Author(s):  
G. L. Kamalov ◽  
D. V. Pozigun ◽  
V. E. Kuz'min ◽  
V. V. Pozigun ◽  
R. N. Lozitskaya
Keyword(s):  
Conformation Analysis ◽  
Alkali Hydrolysis ◽  
Hydrolysis Of ◽  
Theoretical Conformation Analysis ◽  
Tetrahedral Intermediates

scholarly journals Zur Kenntnis der Organophosphorverbindungen, XVI Vinyl-aryldithiophosphinsäuren und einige ihrer Derivate.

1976 ◽  
Vol 31 (4) ◽  
pp. 437-441 ◽  
Author(s):  
Wilhelm Kuchen ◽  
Helmut Keck
Keyword(s):  
Alkali Hydrolysis ◽  
Hydrolysis Of

Vinylaryldithiophosphinic acids RR′P(S)SH (R = vinyl; R′ = p-methoxyphenyl, p-ethoxyphenyl) were obtained as NH4-salts from the reaction of aryldithiophosphonic anhydride with CH2=CHMgBr. Alkali hydrolysis of the methylester RR′P(S)SCH3 (R′ = p-methoxyphenyl) gave β-methylnercaptoethyl-p-methoxyphenylthiophosphinic acid.

scholarly journals Enhanced microbial degradation of irradiated cellulose under hyperalkaline conditions

2020 ◽  
Vol 96 (7) ◽  
Author(s):  
Naji M Bassil ◽  
Joe S Small ◽  
Jonathan R Lloyd
Keyword(s):  
Microbial Degradation ◽  
Degradation Products ◽  
Hydrolysis Product ◽  
Hydrogen Gas ◽  
Cellulose Fibres ◽  
Production Of Hydrogen ◽  
Hydrolysis Of Cellulose ◽  
Alkali Hydrolysis ◽  
Intermediate Level Radioactive Waste ◽  
Hydrolysis Of

ABSTRACT Intermediate-level radioactive waste includes cellulosic materials, which under the hyperalkaline conditions expected in a cementitious geological disposal facility (GDF) will undergo abiotic hydrolysis forming a variety of soluble organic species. Isosaccharinic acid (ISA) is a notable hydrolysis product, being a strong metal complexant that may enhance the transport of radionuclides to the biosphere. This study showed that irradiation with 1 MGy of γ-radiation under hyperalkaline conditions enhanced the rate of ISA production from the alkali hydrolysis of cellulose, indicating that radionuclide mobilisation to the biosphere may occur faster than previously anticipated. However, irradiation also made the cellulose fibres more available for microbial degradation and fermentation of the degradation products, producing acidity that inhibited ISA production via alkali hydrolysis. The production of hydrogen gas as a fermentation product was noted, and this was associated with a substantial increase in the relative abundance of hydrogen-oxidising bacteria. Taken together, these results expand our conceptual understanding of the mechanisms involved in ISA production, accumulation and biodegradation in a biogeochemically active cementitious GDF.

The products of hydrolysis of cyclic orthoesters as a function of pH and the theory of stereoelectronic control

1985 ◽  
Vol 63 (9) ◽  
pp. 2485-2492 ◽  
Author(s):  
Pierre Deslongchamps ◽  
Jean Lessard ◽  
Yves Nadeau
Keyword(s):  
Acid Hydrolysis ◽  
Hydroxy Ester ◽  
The Other ◽  
Relative Percentage ◽  
Stereoelectronic Control ◽  
Hydrolysis Of ◽  
Tetrahedral Intermediates

The acid hydrolysis of cyclic orthoesters 1, 3–6 (R = Me), and 2 (R = Me and Et) as a function of pH was studied. The bicyclic orthoester 5 yields mainly the hydroxy-ester (less than 5% lactone), and this result is essentially independent of pH. For the other orthoesters, the relative percentage of products differs for each case and varies with pH. At pH ≤ 3, the percentage of lactone is always larger than at pH > 3. These results are explained on the basis of the stereoelectronic theory for the cleavage of tetrahedral intermediates.

scholarly journals Bioethanol Production from Paper Fibre Residue Using Diluted Alkali Hydrolysis and the Fermentation Process

2011 ◽  
Vol 8 (4) ◽  
pp. 1951-1957 ◽  
Author(s):  
G. Sathya Geetha ◽  
A. Navaneetha Gopalakrishnan
Keyword(s):  
Reaction Time ◽  
Penicillium Chrysogenum ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Bioethanol Production ◽  
Time Period ◽  
Hydrolysis Of Cellulose ◽  
Alkali Hydrolysis ◽  
Hydrolysis Of ◽  
State Of Art

The state of art for the bioethanol production from paper fibre residue using diluted alkali hydrolysis and fermentation processes was evaluated. Hydrolysis of paper fibre residue with diluted sodium hydroxide at various time period, temperature and concentration were investigated. The paper fibre residue was pre-steamed, impregnated with diluted NaOH (0 to 25%) and subsequently hydrolyzed in a reactor at temperatures that ranged between 30 to 50oC, for reaction time between 30 minutes to 150 minutes. The highest yield of monosaccharide (indicating the efficient hydrolysis of cellulose and hemi cellulose) was found at a temperature of 35oC for a reaction time of 90 minutes. Fermentability of hemicelluloses hydrolysate was tested using monosaccharide fermenting microorganismPenicillium chrysogenumandSaccharomyces cereviacea. The fermentability of the hydrolysate decreased strongly for hydrolysate produced at temperature higher than 50oC. The ethanol concentration of monosaccharide hydrolysate was found to be 34.06 g/L and the ethanol yield was 0.097 g/g.

Sign in / Sign up

Export Citation Format

Share Document