Thermolysis of Δ3-1,3,4-oxadiazolin-2-ones and 2-phenylimino-Δ3-1,3,4-oxadazolines derived from α,β-epoxyketones. An alternative method for the convers of α,β-epoxyketones to alkynones and alkynals

1978 ◽  
Vol 56 (3) ◽  
pp. 308-315 ◽  
Author(s):  
Gerald A. MacAlpine ◽  
John Warkentin
Keyword(s):  
Carbonyl Compounds ◽  
Polar Solvents ◽  
Parallel Decomposition ◽  
Alternative Method ◽  
Aldehydes And Ketones ◽  
Decomposition Pathway

Thermolyses in polar solvents, of Δ3-1,3,4-oxadiazolin-2-ones or 2-phenylimino-Δ3-1,3,4-oxadiazolines derived from α,β-epoxyketones, yields acetylenic carbonyl compounds. Good yields of acetylenic aldehydes and ketones are obtained for those cases in which the epoxide is ring fused. Extension to acyclic cases failed primarily due to predominance of a parallel decomposition pathway. The method complements the procedures developed by Eschenmoser and co-workers for the conversion of, α,β-epoxyketones into acetylenic carbonyl compounds.

scholarly journals Copper(I) Chloride/Kieselguhr: A Versatile Catalyst for Oxidation of Alkyl Halides and Alkyl Tosylates to the Carbonyl Compounds

1999 ◽  
Vol 23 (7) ◽  
pp. 434-435
Author(s):  
Mohammed M. Hashemi ◽  
Yousef Ahmadi Beni
Keyword(s):  
Carbonyl Compounds ◽  
Alkyl Halides ◽  
Aldehydes And Ketones ◽  
High Yields

Copper(I) Chloride adsorbed on Kieselguhr in the presence of oxygen catalyses oxidation of alkyl halides and alkyl tosylates to the aldehydes and ketones in high yields.

scholarly journals Michael addition of carbonyl compounds to nitroolefins under the catalysis of new pyrrolidine-based bifunctional organocatalysts

2018 ◽  
Vol 16 (6) ◽  
pp. 924-935 ◽  
Author(s):  
A. Castán ◽  
R. Badorrey ◽  
J. A. Gálvez ◽  
P. López-Ram-de-Víu ◽  
M. D. Díaz-de-Villegas
Keyword(s):  
Michael Addition ◽  
Carbonyl Compounds ◽  
Asymmetric Michael Addition ◽  
Aldehydes And Ketones

Novel bifunctional pyrrolidine-based organocatalysts applicable for the asymmetric Michael addition of aldehydes and ketones to nitroolefins have been developed.

scholarly journals Synthesis of the O-(2,3,4,5,6-Pentafluorobenzyl)Hydroxylamine Oximes of Selected Carbonyl Compounds and Their Determination by Liquid Chromatography with Ultraviolet Detection

2000 ◽  
Vol 83 (4) ◽  
pp. 859-870 ◽  
Author(s):  
Karina Wiesenthal ◽  
Alexander Jehlar ◽  
Shane S Que Hee
Keyword(s):  
Carbonyl Compounds ◽  
Tap Water ◽  
Hydroxylamine Hydrochloride ◽  
Gradient Elution ◽  
Electron Capture Detection ◽  
Resonance Spectroscopy ◽  
Ultraviolet Detection ◽  
13C Nuclear Magnetic Resonance ◽  
Aldehydes And Ketones ◽  
Synthetic Reaction

Abstract The aims were to develop a liquid chromatographic (LC) method with ultraviolet detection (UVD) for O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) O-oximes of common aldehydes and ketones, and to define the steric limits of the synthetic reaction used to make the PFBHA O-oxime standards for gas chromatographic (GC) and LC methods. Ten new O-oximes were synthesized with the new optimized method, and their purities were demonstrated by GC/electron-capture detection (ECD), GC/mass spectrometry (MS), ultraviolet spectroscopy, infrared spectroscopy, and proton and 13C-nuclear magnetic resonance spectroscopy. Ketones substituted at both β-carbons relative to the carbonyl carbon, like diisobutyl ketone and 2,4-hexanedione, showed lower synthetic yields by wet chemistry methods. A new C18 reverse-phase LC method with UVD at 200 nm and acetonitrile–water in both the isocratic and gradient-elution modes was then developed to sensitively resolve a mixture of 13 pure PFBHA O-oximes. The detection limit was near 100 ng O-oxime/mL or about 14–50 ng aldehyde/mL and the least quantifiable limits were near 500 ng/mL or about 70–250 ng aldehyde/mL, with lower limits for glyoxal, methylglyoxal, benzaldehyde, and acetophenone. Carbonyl compounds in 500 mL water samples were then determined in distilled water and tap water by gradient elution. Vapors of n-valeraldehyde and acrolein generated in gas bags at concentrations near occupational guidelines were also sampled, desorbed, and then determined by either isocratic or gradient elution at 200 or 254 nm within 30–45 min.

44. Degradation of α-amino-acids to aldehydes and ketones by interaction with carbonyl compounds

1948 ◽  
Vol 0 (0) ◽  
pp. 176-182 ◽  
Author(s):  
Alexander Schönberg ◽  
Radwan Moubasher ◽  
Akila Mostafa
Keyword(s):  
Amino Acids ◽  
Carbonyl Compounds ◽  
Aldehydes And Ketones

Hydrogen transfer reactions. I. Reduction of carbonyl compounds by alcohols catalyzed by alumina

1969 ◽  
Vol 47 (19) ◽  
pp. 3705-3707 ◽  
Author(s):  
D. V. Ramana ◽  
C. N. Pillai
Keyword(s):  
Vapor Phase ◽  
Carbonyl Compounds ◽  
Hydrogen Transfer ◽  
Isopropyl Alcohol ◽  
Aromatic Aldehydes ◽  
Transfer Reactions ◽  
Secondary Alcohols ◽  
Effective Catalyst ◽  
Phase Reduction ◽  
Aldehydes And Ketones

Alumina containing about 2.2% by weight of Na+ has been found to be an effective catalyst for the vapor phase reduction of carbonyl compounds by alcohols and for the reverse reaction, the oxidation of the alcohols by carbonyl compounds. The reduction of a number of aliphatic and aromatic aldehydes and ketones by isopropyl alcohol and the oxidation of a number of primary and secondary alcohols by ketones like acetone and cyclohexanone are reported.

scholarly journals Purification and characterization of two forms of microsomal carbonyl reductase in guinea pig liver

1984 ◽  
Vol 223 (3) ◽  
pp. 697-705 ◽  
Author(s):  
S Usui ◽  
A Hara ◽  
T Nakayama ◽  
H Sawada
Keyword(s):  
Carbonyl Compounds ◽  
Gel Filtration ◽  
Carbonyl Reductase ◽  
Cofactor Specificity ◽  
Major Form ◽  
Aldehydes And Ketones ◽  
Minor Form ◽  
Triton X ◽  
Guinea Pig Liver

Two forms of microsomal carbonyl reductase, solubilized in Triton X-100, were purified to homogeneity from the liver of male guinea pigs, primarily by affinity, DEAE-Sephacel, gel-filtration and hydroxyapatite chromatography. The major form was a tetrameric glycoprotein of single subunits of Mr 32000 and a pI value of 7.0; another minor form was a monomeric protein with Mr 34000 and a pI value of 7.8. The enzymes were immunologically distinct. Although the enzymes showed similar substrate specificity for exogenous aldehydes and ketones and apparently absolute cofactor specificity for NADPH, their specificity for natural carbonyl compounds differed. The major form irreversibly reduced 5 alpha- and 5 beta-dihydrotestosterones, menadione and lauryl aldehyde with low Km values of 10-70 microM, whereas the minor form not only reduced 17-oxosteroids, of which 3 alpha-hydroxy-5 beta-androstan-17-one was the best substrate, but also oxidized 17-hydroxysteroids in the presence of NADP+. The two forms of carbonyl reductase also exhibited different sensitivity to heavy metal ions, dicoumarol, tetramethyleneglutaric acid, phenobarbitone and corticosteroids.

A simple and efficient method for the synthesis of gem-diacetates from aldehydes and ketones catalysed by gallium triiodide

2005 ◽  
Vol 2005 (10) ◽  
pp. 659-660 ◽  
Author(s):  
Peipei Sun ◽  
Zhixin Hu
Keyword(s):  
Acetic Anhydride ◽  
Ambient Temperature ◽  
Efficient Method ◽  
Carbonyl Compounds ◽  
Aldehydes And Ketones

Aldehydes or ketones reacted with acetic anhydride in dichloromethane at ambient temperature to produce gem-diacetates in good to excellent yields in the presence of gallium triiodide, which was generated in situ from gallium and iodine. This catalyst was also useful for the deprotection of carbonyl compounds in the presence of water.

Mild and Convenient Method for Reduction of Carbonyl Compounds with the NaBH4/Charcoal System in Wet THF

2006 ◽  
Vol 61 (10) ◽  
pp. 1275-1281 ◽  
Author(s):  
Davood Setamdideh ◽  
Behzad Zeynizadeh
Keyword(s):  
Convenient Method ◽  
Carbonyl Compounds ◽  
Aprotic Solvent ◽  
Reduction Reactions ◽  
Unsaturated Aldehydes ◽  
Aldehydes And Ketones

The NaBH4/C (charcoal) system reduces a variety of carbonyl compounds such as aldehydes, ketones, acyloins and α-diketones to their corresponding alcohols in high to excellent yields. Reduction reactions were carried out in wet THF at r. t. In addition, regioselective 1,2-reduction of α,β - unsaturated aldehydes and ketones was achieved perfectly with this reducing system. By decreasing the amount of aprotic solvent, all reductions took place fast and efficiently under solid-gel condition

scholarly journals Polystyrene-supported aluminum chloride as an efficient and reusable catalyst for condensation of indole with various carbonyl compounds

2010 ◽  
Vol 75 (4) ◽  
pp. 423-431 ◽  
Author(s):  
Bahman Tamami ◽  
Nasrolahi Shirazi ◽  
Parvanak Borujeni
Keyword(s):  
Aluminum Chloride ◽  
Carbonyl Compounds ◽  
Low Cost ◽  
Reaction Times ◽  
Reusable Catalyst ◽  
Reaction Conditions ◽  
Crosslinked Polystyrene ◽  
Aldehydes And Ketones ◽  
Polymeric Catalyst ◽  
Work Up

Crosslinked polystyrene-supported aluminum chloride (Ps-AlCl3) is a stable, recyclable and environmental friendly heterogeneous catalyst for the condensation of indole with aldehydes and ketones to afford bis-indolylmethanes. In addition, (Ps-AlCl3) shows satisfactory selectivity in the reaction of mixtures of an aldehyde and a ketone with indole. Although AlCl3 is a water sensitive, corrosive and environmentally harmful compound, Ps-AlCl3 is a stable and water-tolerant species. The mild reaction conditions, short reaction times, easy work-up, high to excellent yields, chemoselectivity, reuse of the catalyst for at least ten times without significant change in its catalytic activity, low cost, and easy preparation and handling of the polymeric catalyst are obvious advantages of the present method.

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