Reactions of Hydrogen Peroxide. IV. Sodium Tungstate Catalyzed Epoxidation of α,β-Unsaturated Acids

1959 ◽  
Vol 24 (1) ◽  
pp. 54-55 ◽  
Author(s):  
GEORGE B. PAYNE ◽  
PAUL H. WILLIAMS
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Tungstate

Preparation of 4-Hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl A Reinvestigation of Methods Using Hydrogen Peroxide in the Presence of Catalysts

1976 ◽  
Vol 31 (10) ◽  
pp. 1376-1378 ◽  
Author(s):  
G. Sosnovsky ◽  
M. Konieczny
Keyword(s):  
Hydrogen Peroxide ◽  
Phosphotungstic Acid ◽  
Sodium Tungstate ◽  
Spin Labeling ◽  
Quantitative Yield ◽  
Hydrogen Peroxide Solution ◽  
Aqueous Hydrogen Peroxide ◽  
Molar Excess

The preparation of the key intermediate for spin labeling, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (2), was reinvestigated using sodium tungstate or phosphotungstic acid with or without either Trilon or Triton B. A two-fold and a 3.5-fold molar excess of a 30% aqueous hydrogen peroxide solution was used. The oxidation of 4-hydroxy-2,2,6,6-tetramethylpiperidine (1) with a two-fold molar excess of a 30% aqueous hydrogen peroxide solution in the presence of sodium tungstate alone, under vigorous stirring for two hours, is the superior method (A) for the preparation of 2 in virtually quantitative yield.

Kinetics of the oxidation of dimethyl sulfoxide with aqueous hydrogen peroxide catalyzed by sodium tungstate

1981 ◽  
Vol 59 (4) ◽  
pp. 718-722 ◽  
Author(s):  
Yoshiro Ogata ◽  
Kazushige Tanaka
Keyword(s):  
Hydrogen Peroxide ◽  
Dimethyl Sulfoxide ◽  
Sodium Tungstate ◽  
Catalytic Amount ◽  
Active Oxygen ◽  
Probable Mechanism ◽  
Polarographic Study ◽  
Aqueous Hydrogen Peroxide ◽  
First Order ◽  
Kinetics Of

The oxidation of dimethyl sulfoxide (DMSO) by hydrogen peroxide in the presence of a catalytic amount of sodium tungstate (Na2WO4) has been studied kinetically by means of iodometry of hydrogen peroxide. The reaction is first-order with respect to the substrate and the catalyst, but independent of the concentration of hydrogen peroxide which is present in excess of the catalyst. The polarographic study implies that in solutions two main kinds of peroxytungstic acids (H2WO5 and H2WO8) are formed which contain active oxygen in ratios (active oxygen):(Na2WO4) of 1:1 and 4:1, respectively. The effect of acidity on the oxidation rate and a probable mechanism involving a rate-determining attack of peroxytungstic acids are discussed.

Oxidative Iodination of Aromatic Amides Using Sodium Perborate or Hydrogen Peroxide with Sodium Tungstate†

1998 ◽  
pp. 204-205 ◽  
Author(s):  
Philipp Beinker ◽  
James R. Hanson ◽  
Nadja Meindl ◽  
Inmaculada C. Rodriguez Medina
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Tungstate ◽  
Sodium Perborate ◽  
Oxidative Iodination

scholarly journals Attempted Synthesis and Unexpected β-Fragmentation of a Hindered β-Keto Nitroxide

2017 ◽  
Vol 70 (10) ◽  
pp. 1106 ◽  
Author(s):  
Chris Edwards ◽  
Peter C. Healy ◽  
W. Ken Busfield ◽  
Ezio Rizzardo ◽  
San H. Thang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Ring Opening ◽  
Sodium Tungstate ◽  
Crystallographic Analysis ◽  
High Yield ◽  
Fragmentation Mechanism ◽  
Pentanoic Acid ◽  
X Ray ◽  
Ring Opening Reaction

The attempted synthesis of a β-keto imidazolidinone nitroxide by oxidation of the β-hydroxy imidazolidinone precursor with hydrogen peroxide and sodium tungstate led to an unexpected ring-opening reaction to produce 1,4-diazaspiro[4.5]dec-1-en-3-oxo-2-pentanoic acid 1-oxide (13) in high yield. The structure of 13 was confirmed by X-ray crystallographic analysis. A β-fragmentation mechanism is suggested for the oxidative ring-opening reaction.

scholarly journals DELIGNIFICATION OF FLAX SHIVE

2017 ◽  
pp. 155-162 ◽  
Author(s):  
Наталья (Natal'ja) Викторовна (Viktorovna) Каретникова (Karetnikova) ◽  
Лариса (Larisa) Валерьевна (Valer'evna) Чендылова (Chendylova) ◽  
Роберт (Robert) Зусьевич (Zus'evich) Пен (Pen)
Keyword(s):  
Hydrogen Peroxide ◽  
Catalyst Concentration ◽  
Sodium Tungstate ◽  
Heat Insulation ◽  
Hot Water ◽  
Pulp Yield ◽  
Complex Catalyst ◽  
Initial Concentration ◽  
Mass Part ◽  
Catalyst Composition

Delignification of the flax shive (wastes of oakum and heat insulation production) was studied. Chemical composition of the work material (mass parts in percents from the bone-dry material): cellulose 30,7, lignin 33,1, pentosans 28,0, extractable by organic solvent 4,3, extractable by hot water 5,4, ash 1,7. The flax shive was delignificated in laboratory condition by means of peracetic acid, hydrogen peroxide and sulfate cooking solution. The conditions of peracetic pulping: initial mass part of the «icy» acetic acid in cooking solution 0,65, perhydrol 0,35, the catalyst concentration (sodium tungstate) 0,03 g-mol/dm3, liquid module 6, temperature 92 °C; pulp yield 46,1% without of undercooked pulp. The conditions of peroxide pulping: initial concentration of hydrogen peroxide 17%, liquid module 6, complex catalyst concentration 0,1 g-mol/dm3 (molar parts of the Na2WO4, Na2MoO4 and H2SO4 in catalyst composition are 0,3 : 0,3 : 0,4 accordingly), temperature 98 °C; pulp yield 45,8% without undercooked pulp. The conditions of sulfate pulping: initial concentration of active alkali 55 g/dm3 (in Na2O unit), degree of sulfidity 18%, liquid module 4, temperature 170 °C; pulp yield 32,3% without undercooked pulp. Samples of the technical cellulose, received by oxidizing methods, excel sulphate cellulose in relation to yield, ability for milling, whiteness and mechanical properties (except for tear). On the set of normalized properties they approach to characteristic of kraft bleached pulp from deciduous woods and can be considered as perspective stringy half-finished for production of the paper sanitary-household and hygienic purpose.

Synthesis of 2,3-Anhydro Glycosyl Phosphonates

1996 ◽  
Vol 49 (3) ◽  
pp. 371 ◽  
Author(s):  
m Doanxuanlie ◽  
ID Jenkins ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Hydrogen Peroxide ◽  
Structural Analysis ◽  
Sodium Tungstate ◽  
X Ray

The synthesis of dimethyl 6-O-acetyl-2,3-anhydro-α-D- mannopyranosylphosphonates and the corresponding α- and β- allo derivatives is described. Dimethyl 4,6-di-O-acetyl-2,3-dideoxy-D-erythro-hex-2-enopyranosylphosphonates, although unreactive towards normal epoxidizing agents (3-chloroperoxybenzoic acid, trifluoroperoxyacetic acid, etc), underwent smooth epoxidation with hydrogen peroxide in the presence of sodium tungstate or dodecatungstophosphoric acid. An interesting regiospecific deacetylation of the 4-acetate occurred under these conditions. The structures of these anhydro glycosyl phosphonates were determined by 1H and 13C n.m.r. spectroscopy, and confirmed by X ray structural analysis in the case of dimethyl 6-O-acetyl-2,3-anhydro-α-D-mannopyranosylphosphonate , and of dimethyl 6-O-acetyl-2,3-anhydro-β-D-allopyranosylphosphonate.

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