Parent Carbonyl Compounds Research Articles

A MILD AND SELECTIVE DEOXIMATION METHOD USING γ-PICOLINIUM CHLOROCHROMATE (γ-PCC)

ABSTRACT A mild and efficient method for the oxidative conversion of oximes to their parent carbonyl compounds with γ-picolinium chlorochromate (γ-PCC) under non-aqueous conditions is described.

A Useful and Catalytic Method for Protection of Carbonyl Compounds into the Corresponding 1,3-Oxathiolanes and Deprotection to the Parent Carbonyl Compounds

A wide variety of carbonyl compounds 1 can be easily protected to the corresponding 1,3-oxathiolanes 2 in good yields in the presence of catalytic amount of perchloric acid in dry CH 2 Cl 2 at 0-5 °C. On the other hand, various 1,3-oxathiolanes 2 can be selectively deprotected to the parent carbonyl compounds 1 in very good yields by H 2 MoO 4 .H 2 O-H 2 O 2 catalyzed oxidation of ammonium bromide in the presence of perchloric acid in CH 2 Cl 2 -H 2 O solvent system. Mild reaction condition, high selectivity, efficient and relatively good yields are some of the major advantages of the procedure.

Oxidative Deprotection of Oximes with Peroxodisulfate under Heterogeneous Conditions1

A reagent combination of (NH4)2S2O8, a catalytic amount of AgNO3, in general, or Cu(NO3)2in particular, and moist montmorillonite K10 clay in hexane regenerates the parent carbonyl compounds in high yields under relatively mild conditions.

An Expedient and Efficient Method for the Cleavage of Dithioacetals to the Corresponding Carbonyl Compounds Using Organic Ammonium Tribromide (OATB)

A variety of dithioacetals of aldehydes or ketones 1 can be easily cleaved into the parent carbonyl compounds 2 at 0-5 °C in very high yields by employing organic ammonium tribromides such as cetyltrimethyl-ammonium tribromide (CetTMATB) or tetrabutylammonium tribromide (TBATB) in dichloromethane.

Regeneration of Carbonyl Compounds from Oximes and Hydrazones Using Peroxymonosulfate on Silica gel under Solvent-free Conditions

In an environmentally benign solvent-free system, oximes and hydrazones are rapidly transformed into parent carbonyl compounds using peroxymonosulfate on silica gel under microwave irradiation in good to excellent yields.

Determination of Thiosemicarbazones by Means of the Induced Iodine-Azide Reaction

The iodine-azide reaction induced by eight thiosemicarbazones was investigated. Inducing properties of thiosemicarbazones are different and depend on the parent carbonyl compound used for synthesis. The inductor coefficients of the examined thiosemicarbazones vary from 61 to 176. Optimum conditions for the determination of microamounts of thiosemicarbazones are given. The detection limit for the determination by the back-titration method depends on the inducing activity and is 0.9 μg for phenyl-thiosemicarbazones and 2 μg for diethyl-thiosemicarbazone in a 5-mL sample, and this corresponds to a concentration of 0.9 × 10−6 mol/L and \(\), respectively. The automatic titration with the diluted iodine solution decreases the detection limit to about 50 ng in a 10-mL sample.

Regeneration of Carbonyl Compounds by Oxidative Cleavage of Hydrazones with Zr(O-t-Bu)4/tert-Butyl Hydroperoxide

A catalytic method with Zr(O-t-Bu)4 as the catalyst and tert-butyl hydroperoxide as the oxidant is described to cleave phenylhydrazones 6—9, 14—16 to the parent carbonyl compounds under mild and neutral oxidative conditions.

Indium-mediated reductive dehalogenation of α-halocarbonyl compounds in water†

Reactions of various α-halocarbonyl compounds 1 with indium in the presence of a catalytic amount of sodium dodecyl sulfate in water were performed to afford the corresponding parent carbonyl compounds 2 in excellent yields.

Preparative conversion of oximes to parent carbonyl compounds by cerium(IV) sulfate in acetonitrile and alcohol

A new method for the direct conversion of oximes into aldehydes and ketones by treatment with cerium(IV) salts is described. Cerium(IV) salts can be used as an effective and mild oxidizing agent for the regeneration of carbonyl compounds from oximes in good yield. The solvent effects are discussed. Copyright © 1999 John Wiley & Sons, Ltd.

Iodine as a New Deoximating Agent

Iodine is found to he an effective and mild reagent for conversion of aldoximes and ketoximes to their parent carbonyl compounds.

ChemInform Abstract: Trimethylammonium Chlorochromate Adsorbed on Alumina: An Efficient and Convenient Reagent for the Oxidative Cleavage of 4‐Phenylsemicarbazones and Semicarbazones to Their Parent Carbonyl Compounds.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Trimethylammonium Chlorochromate Adsorbed on Alumina: An Efficient and Convenient Reagent for the Oxidative Cleavage of 4-Phenylsemicarbazones and Semicarbazones to Their Parent Carbonyl Compounds

Deprotection of 4-phenylsemicarbazones and semicarbazones to their parent aldehydes and ketones in high yields has been carried out by using trimethylammonium chlorochromate adsorbed on alumina as selective oxidant under mild conditions.

Identification of the reactive cysteine residue (Cys227) in human carbonyl reductase.

Carbonyl reductase is highly susceptible to inactivation by organomercurials suggesting the presence of a reactive cysteine residue in, or close to, the active site. This residue is also close to a site which binds glutathione. Structurally, carbonyl reductase belongs to the short-chain dehydrogenase/reductase family and contains five cysteine residues, none of which is conserved within the family. In order to identify the reactive residue and investigate its possible role in glutathione binding, alanine was substituted for each cysteine residue of human carbonyl reductase by site-directed mutagenesis. The mutant enzymes were expressed in Escherichia coli and purified to homogeneity. Four of the five mutants (C26A, C122A C150A and C226A) exhibited wild-type-like enzyme activity, although K(m) values of C226A for three structurally different substrates were increased threefold to 10-fold. The fifth mutant, C227A, showed a 10-15-fold decrease in kcat and a threefold to 40-fold increase in K(m), resulting in a 30-500-fold drop in kcat/K(m). NaCl (300 mM) increased the activity of C227A 16-fold, whereas the activity of the wild-type enzyme was only doubled. Substitution of serine rather than alanine for Cys227 similarly affected the kinetic constants with the exception that NaCl did not activate the enzyme. Both C227A and C227S mutants were insensitive to inactivation by 4-hydroxymercuribenzoate. Unlike the parent carbonyl compounds, the glutathione adducts of menadione and prostaglandin A1 were better substrates for the C227A and C227S mutants than the wild-type enzyme. Conversely, the binding of free glutathione to both mutants was reduced. Our findings indicate that Cys227 is the reactive residue and suggest that it is involved in the binding of both substrate and glutathione.

ChemInform Abstract: Oxidative Deoximation to Their Parent Carbonyl Compounds with Ammonium Chlorochromate Adsorbed on Alumina.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Oxidative Deoximation to Their Parent Carbonyl Compounds with Ammonium Chlorochromate Adsorbed on Alumina

A convenient method for the oxidative cleavage of oximes to their parent aldehydes and ketones with ammonium chlorochromate adsorbed on alumina is described

Correlations Des DéPlacements Chimiques En Rmn 13C De ComposéS Carbonyles, Thiocarbonyles Et Selenocarbonyles

The 13C chemical shifts of ketones, thioketones and selenoketones are presented. Various relations for the prediction of thiocarbonyl (selenocarbonyl) shifts from the C=O shift values of the parent carbonyl compounds are discussed.

Oxidative Dimerization of Phenylhydrazones by Nickel Peroxide

Phenylhydrazones were oxidized by nickel peroxide at 0 °C through a radical mechanism to afford C-C and C-N dimers in nearly 1:2 ratio in excellent yields. The C-N dimer either decomposed under acidic conditions in CDCl3 to give the parent phenylhydrazone and carbonyl compounds or, upon heating, underwent rearrangement to form the corresponding C-C dimer.

Efficient and Mild Regeneration of Carbonyl Compounds from Oximes and Hydrazones by Manganese(iii) Porphyrin–Periodate

The periodate–manganese tetraphenylporphyrin, Mn(tpp)/IO4–, catalytic system is efficient in regenerating the parent carbonyl compounds from oximes and phenylhydrazones at room temperature.

A Convenient Deprotection of 1,3-Dithiane Derivatives with Ferric Nitrate Under Heterogeneous Conditions

1,3-Dithianes derived from aromatic, aliphatic, and alicyclic ketones or aldehydes can be conveniently converted to the parent carbonyl compounds with a combination of ferric nitrate and silica gel in hexane in excellent to quantitative yields.

Observation of secondary 2-butene ozonide in the ozonation of trans-2-butene in the gas phase

GC/MS detection of secondary 2-butene ozonide in the gas-phase ozonation of trans-2-butene provides the first conclusive evidence on the feasibility of the combination of Criegee intermediate with parent carbonyl compound, which is not facilitated by solvent.