Septanose Carbohydrates. III. Oxidation-Reduction Products From 1,2-3,4-Di-O-isopropylidene-α-D-glucoseptanose: Preparation of L-Idose Derivatives

1990 ◽  
Vol 43 (12) ◽  
pp. 2063 ◽  
Author(s):  
GE Driver ◽  
JD Stevens
Keyword(s):  
Acetic Anhydride ◽  
Dimethyl Sulfoxide ◽  
Acid Hydrolysis ◽  
Sodium Methoxide ◽  
Aqueous Acid ◽  
Methylmagnesium Iodide ◽  
Oxidation Reduction ◽  
Hydrolysis Of

Oxidation of 1,2:3,4-di-O-isopropylidene-α-D-glucoseptanose (1a) with dimethyl sulfoxide and acetic anhydride has yielded methylthiomethyl ether (1b), ketone (2), and a novel product (3). Reduction of (2) gave (1a) and its L-ido isomer (4a) which yielded the mono-O-isopropylidene compound (5a) on aqueous acid hydrolysis. Treatment of (5a) with acidified acetone gave (4a) and 1,2:4,5-di-O-isopropylidene-β-L- idoseptanose (7a). Reaction of (2) with methylmagnesium iodide yielded the two 5-C-methyl compounds (8) and (9). Hydrolysis of (8) and (9) gave 5-C-methyl-D-glucose (10) and 5-C-methyl-L-idose (11), respectively, as crystalline compounds which yielded crystalline pentaacetates on acetylation. Treatment of the p-toluenesulfonate (1c) with lithium benzoate in dimethylformamide gave the benzoate of (4a) and an elimination product (17). Reaction of (1c) with sodium methoxide in methanol yielded (17) and the isomeric elimination product (18).

scholarly journals Oxidation–reduction reactions of simple hydroxamic acids and plutonium(IV) ions in nitric acid

2008 ◽  
Vol 96 (6) ◽  
Author(s):  
M. J. Carrott ◽  
O. D. Fox ◽  
G. LeGurun ◽  
C. J. Jones ◽  
C. Mason ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Kinetic Studies ◽  
Hydroxamic Acids ◽  
Single Cycle ◽  
Fuel Cycles ◽  
Oxidation Reduction ◽  
Advanced Fuel ◽  
Extraction Processes ◽  
The Stability ◽  
Hydrolysis Of

SummarySimple hydroxamic acids such as formo- and aceto-hydroxamic acids have been proposed as suitable reagents for the separation of either Pu and/or Np from U in modified or single cycle Purex based solvent extraction processes designed to meet the emerging requirements of advanced fuel cycles. The stability of these hydroxamic acids is dominated by their decomposition through acid hydrolysis. Kinetic studies of the acid hydrolysis of formo- and aceto-hydroxamic acids are reported in the absence and the presence of Pu(IV) ions. The slow reduction of these plutonium(IV) hydroxamate complexes to Pu(III) aquo-ions has been characterised by spectrophotometry and cyclic voltammetry. The reductions of Pu(IV) in the presence of FHA and AHA are consistent with a mechanism in which free hydroxamic acid in solution is hydrolysed whilst Pu(IV) ions remain fully complexed to hydroxamate ligands; then at some point close to a 1 : 1 Pu(IV) : XHA ratio, some free Pu

Potential antidepressants: 2-(Aminoalkoxy)biphenyls and some related ω-substituted 2-alkoxybiphenyls

1989 ◽  
Vol 54 (7) ◽  
pp. 1966-1978 ◽  
Author(s):  
Irena Červená ◽  
Jiří Holubek ◽  
Emil Svátek ◽  
Jan Metyš ◽  
Miroslav Protiva
Keyword(s):  
Dimethyl Sulfoxide ◽  
Acid Hydrolysis ◽  
Sodium Cyanide ◽  
Secondary Amines ◽  
Hydrolysis Of ◽  
Bromo Compound

Reactions of 2-hydroxybiphenyl with α,ω-dibromoalkanes gave the 2-(bromoalkoxy)biphenyls IIIa-IIId. The 2-(dimethylaminoalkoxy)biphenyls VIa and VIb were transformed via carbamates VIIa and VIIb to the secondary amines Va and Vb. Their homologues Vc and Vd were obtained from the bromo compounds IIIc and IIId by treatment with methylamine. Bromo compounds IIIa and IIIb were reacted with 1-methylpiperazine, 2-(1-piperazinyl)ethanol, 3-(1-piperazinyl)propanol, and 4-amino-1-benzylpiperidine and gave the diamines VIIIa, VIIIb, IXa, Xa, Xb, and XIa. Addition of 2-hydroxybiphenyl to acrylonitrile afforded the nitrile XIIa. The homologous nitrile XIIb was obtained from the bromo compound IIIb and sodium cyanide in dimethyl sulfoxide. Nitriles XIIa and XIIb were reduced with aluminium hydride to diamines IVb and IVc. The nitriles were also transformed to hydrochlorides of the corresponding ethyl imidates XIVa and XIVb. Their hydrolysis resulted in the esters XVa and XVb. The acid XIIIa was obtained by acid hydrolysis of the nitrile XIIa; the acid XIIIb resulted from the acid hydrolysis of the ester XVb. The imidate XIVb was transformed to the amidine XVIb and to the dihydroimidazole XVIIb. Only the amine Vc showed properties indicative of potential antidepressant.

Kinetics of Aqueous Acid Hydrolysis of Iron(III) 5-Substituted-8-Hydroxyquinoline Complexes: Mechanistic Implications

2002 ◽  
Vol 3 (3) ◽  
pp. 153-172 ◽  
Author(s):  
Hakim Boukhalfa ◽  
Fabrice Thomas ◽  
Guy Serratrice ◽  
Claude G. Béguin
Keyword(s):  
Acid Hydrolysis ◽  
Aqueous Acid ◽  
Kinetics Of ◽  
Hydrolysis Of

Total Synthesis of DL-Glucose, 3-O-Methyl-DL-glucose, and 3-Deoxy-DL-ribo-hexopyranose from 1,6:3,4-Dianhydro-β-DL-allo-hexopyranose, a Product Obtained from Acrolein Dimer

1971 ◽  
Vol 49 (20) ◽  
pp. 3342-3347 ◽  
Author(s):  
U. P. Singh ◽  
R. K. Brown
Keyword(s):  
Total Synthesis ◽  
Acid Hydrolysis ◽  
Sodium Methoxide ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Barium Hydroxide ◽  
Lithium Aluminum ◽  
Methyl Glycoside ◽  
Acid Catalyzed ◽  
Hydrolysis Of

The reaction of butyllithium in ether with 1,6:2,3-dianhydro-4-deoxy-β-DL-ribo-hexopyranose (1), a substance obtained in five steps from acrolein dimer, gave 1,6-anhydro-3,4-dideoxy-β-DL-erythro-hex-3-enopyranose (2). The compound 1,6:3,4-dianhydro-β-DL-allo-hexopyranose (3), obtained from 2, was converted by reaction with aqueous barium hydroxide followed by hydrolysis of the product, to DL-glucose 5. Treatment of 3 with sodium methoxide in methanol followed by acid hydrolysis of the 1,6-anhydro intermediate 6, gave 3-O-methyl-DL-glucose (7). The same intermediate, 6, along with the methyl glycoside 8, could be obtained by the acid-catalyzed reaction of 3 with methanol. Lithium aluminum hydride reacted with 3 to form 1,6-anhydro-3-deoxy-β-DL-ribo-hexopyranose (9), which was hydrolyzed readily to 3-deoxy-DL-ribo-hexopyranose (10).Yields were excellent throughout. All products obtained from the oxirane 3 were those resulting only from trans diaxial opening of the oxirane ring.

Nucleosides LIII Syntheses and Reactions of 6,7-Dipyridyllumazine and 2' -Deoxylumazine N-1 Nucleosides

Pteridines ◽  
1993 ◽  
Vol 4 (3) ◽  
pp. 119-125 ◽  
Author(s):  
Najim AL. Al-Masoudi ◽  
Wolfgang Pfleiderer
Keyword(s):  
Acid Hydrolysis ◽  
Sodium Methoxide ◽  
Diphenyl Carbonate ◽  
Acetyl Bromide ◽  
Hydroxide Ion ◽  
Hydrolysis Of ◽  
Direct Condensation

Summary The chemical syntheses of 6,7-(α-pyridyl)-1-(2,3,5-tri-O-benzoy-β-D-ribofuranosyl)-lumazine (6) and the corresponding free nucleoside 7 are described. Thiation of 6 with P4S10 gave a salt type adduct derivative of 4-thiolumazine 8 which afforded the free nucleoside 9 on deblocking. Treatment of 8 with methanolic NH3 gave the isopterin-N-1 nucleoside 10. 2,2' -Anhydro compound 13 was obtained by the diphenyl carbonate technique and characterised as the diacetate 14. Acid hydrolysis of 14 gave the arabino-nucleoside 15. which was isolated also from hydrolysis of 14 with hydroxide ion. Reaction of 7 with acetyl bromide gave the 2'-bromo-2'-deoxy derivative 11 as minor product together with triacetate 12 as the main analogue. Reduction of the bromo function in 11 into the expected 2'-deoxy analogue during the treatment with tri-n-butyltin hydride has failed and the 2.2' -anhydro compound 15 was the only product isolated. Alternatively. the 6,7-bis-(α-pyridyl)-1-(2-deoxy-3.5-di-O-toloulyl-α and β-D-ribofuranosyl)-Iumazine (17) and (19) were synthesized from direct condensation of sugar 16 and the silylated base 4. Debolcking of 17 and 19 with sodium methoxide gave the free analogues 18 and 20 respectively.

The aminolysis of p-nitrophenyl acetate by aminopyridines. Mechanisms in aqueous and aprotic solvents

1980 ◽  
Vol 33 (11) ◽  
pp. 2441 ◽  
Author(s):  
LW Deady ◽  
WL Finlayson
Keyword(s):  
Acetic Anhydride ◽  
Dimethyl Sulfoxide ◽  
Amino Nitrogen ◽  
Base Catalysis ◽  
Aprotic Solvents ◽  
Nucleophilic Catalysis ◽  
General Base ◽  
Amide Formation ◽  
Ring Nitrogen ◽  
Hydrolysis Of

In dimethyl sulfoxide, the aminolysis of p-nitrophenyl acetate by aminopyridines results in amide formation, through nucleophilic catalysis by the ring nitrogen for 4-aminopyridine, but by direct amino nitrogen attack for 2-aminopyridine (as previously found for acetic anhydride). In water, the aminopyridines catalyse the hydrolysis of the ester (unlike aniline, which still gives acetanilide). In general, this occurs by nucleophilic catalysis by the ring nitrogen. Even 4-amino-2- methylpyridine reacts by this route (though 2-picoline does not) and, of the compounds studied, only for 2-amino- 6-methylpyridine does general base catalysis occur instead. Reasons for these mechanism changes are discussed.

DETERMINATION OF MICRO-AMOUNTS OF 5β-PREGNAN-3α-OL-20-ONE IN URINE USING INFRARED-SPECTROMETRY

1962 ◽  
Vol 41 (2) ◽  
pp. 234-246 ◽  
Author(s):  
H. J. van der Molen
Keyword(s):  
Infrared Spectrum ◽  
Quantitative Determination ◽  
Acid Hydrolysis ◽  
Chromatographic Separation ◽  
Pure Form ◽  
Infrared Spectrometry ◽  
Hydrolysis Of

ABSTRACT A procedure for the quantitative determination of 5β-pregnan-3α-ol-20-one in urine is described. After acid hydrolysis of the pregnanolone-conjugates in urine, the free steroids are extracted with toluene. Pregnanolone is isolated in a pure form as its acetate; after chromatographic separation of the free steroids on alumina, the fraction containing pregnanolone is acetylated and rechromatographed on alumina. Quantitative determination of the isolated pregnanolone-acetate is carried out with the aid of the infrared spectrum recorded by a micro KBr-wafermethod. The reliability of the method under various conditions is discussed under the headings, specificity, accuracy, precision and sensitivity. It is possible to determine 30–40 μg pregnanolone in a 24-hours urine portion with a precision of 25%.

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