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Corresponding Ketones (corresponding + ketone)
Selected AbstractsOne-Step Synthesis of Aromatic Terminal Alkynes from Their Corresponding Ketones under Microwave Irradiation.CHEMINFORM, Issue 46 2006Mohammad Ghaffarzadeh Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Designer drug 2,4,5-trimethoxyamphetamine (TMA-2): Studies on its metabolism and toxicological detection in rat urine using gas chromatographic/mass spectrometric techniquesJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 9 2006Andreas H. Ewald Abstract Studies are described on the metabolism and the toxicological detection of the amphetamine-derived designer drug 2,4,5-trimethoxyamphetamine (TMA-2) in rat urine using gas chromatographic/mass spectrometric (GC/MS) techniques. The identified metabolites indicated that TMA-2 was metabolized by oxidative deamination to the corresponding ketone followed by reduction to the corresponding alcohol, O -demethylation followed by oxidative deamination, and finally O,O -bis-demethylation. All metabolites carrying hydroxy groups were found to be partly excreted in urine as glucuronides and/or sulfates. The authors' systematic toxicological analysis (STA) procedure using full-scan GC/MS after acid hydrolysis, liquid-liquid extraction, and microwave-assisted acetylation allowed the detection, in rat urine, of an intake of TMA-2 that corresponds to a common drug users' dose. Assuming similar metabolism, the described STA procedure in human urine should be suitable as proof of an intake of TMA-2. Copyright © 2006 John Wiley & Sons, Ltd. [source] Synthesis of Some Trifluoromethylated Cyclodextrin Derivatives and Analysis of Their Properties as Artificial Glycosidases and OxidasesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 4 2007Jeannette Bjerre Abstract Cyclodextrin derivatives containing trifluoromethyl groups at C6 of the A and D rings were synthesized for the purpose of creating artificial enzymes. The compounds were synthesized by perbenzylation of ,-cyclodextrin followed by selective A,D-debenzylation according to Sina˙. Subsequent oxidation to dialdehyde with Dess,Martin periodinane followed by addition of CF3 by using Arduengo carbene and TMSCF3 led to the C6 -bistrifluoromethylated alcohols. These were either deprotected by hydrogenolysis or subjected to another round of oxidation to provide the corresponding ketones that were deprotected. The trifluoromethylated alcohols were found to be weak artificial enzymes catalysing hydrolysis of nitrophenyl glycosides at neutral pH with a kcat/kuncat of up to 56. It is proposed that this catalysis is analogues to the catalysis performed by related cyanohydrins. The trifluoro ketones were likewise weak articial enzymes catalysing oxidation of amines to nitro derivatives or alcohols to ketones with a kcat/kuncat of up to 133. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Oxidation of Alcohols and vic -Diols with H2O2 by Using Catalytic Amounts of N -Methylpyrrolidin-2-one HydrotribromideEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 3 2006Jomy K. Joseph Abstract A variety of secondary alcohols, 1,2-diols and primary alcohols were selectively oxidized in excellent yields to their corresponding ketones, 1,2-diketones and aldehydes with aqueous 30,% hydrogen peroxide in refluxing acetonitrile in the presence of catalytic amounts of N -methylpyrrolidin-2-one hydrotribromide (MPHT). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Thermal decomposition of cyclic organic peroxides in pure solvents and binary solvent mixturesINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 6 2010Mariángeles Iglesias The thermal decomposition reaction of acetone cyclic triperoxide, acetone cyclic diperoxide, 4-heptanone cyclic diperoxide, and pinacolone cyclic diperoxide ca. 0.02 M was studied in pure solvents (acetone and 1-propanol) and in binary mixtures of acetone/1-propanol at 150°C. The kinetics of each system was explored by gas chromatography (GC) at different solvent compositions. The reactions showed a behavior accordingly with a pseudo-first-order kinetic law up to at least 90% peroxide decomposition. The main organic products derived from these thermolysis reactions were detected by GC analysis. Among them, the corresponding ketones, methane, ethane, and propane were the main identified products. The rates of decomposition of pinacolone diperoxide in the pure solvents were practically independent of the solvent characteristics, so it was of no interest to analyze its kinetic behavior in binary solvent mixtures. In acetone/1-propanol mixtures, the solvation effect on the cyclic peroxides derived from 4-heptanone and acetone molecules was slightly dominated by specific interactions between 1-propanol and a diradical-activated complex initially formed. This species was preferentially solvated by 1-propanol instead of acetone. Specific interactions between the O atoms from the peroxidic bond and the H from the OH in 1-propanol can be taken into account. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 347,353, 2010 [source] One-Pot Synthesis of Carbamoyl Azides Directly from Primary Alcohols and Oxidation of Secondary Alcohols to Ketones Using Iodobenzene Dichloride in Combination with Sodium AzideADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Xiao-Qiang Li Abstract An effective synthesis of carbamoyl azides directly from primary alcohols using iodobenzene dichloride in combination with sodium azide has been developed. Moreover, the same regent combination was also efficient for the oxidation of secondary alcohols to the corresponding ketones. [source] Highly Stereoselective Halocyclopropanation of ,,,-Unsaturated AmidesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2009Abstract A convenient highly stereoselective synthesis of chloro- and bromocyclopropanamides from di- tri- or tetrasubstituted (E)- or (Z)-,,, - unsaturated amides with total or high stereoselectivity promoted by chromium dichloride or dibromide is described. The transformation of chlorocyclopropanamides into the corresponding ketones or amines is also reported. A mechanism to explain these transformations is proposed. [source] Enantioselective Synthesis of 4-(Dimethylamino)pyridines through a Chemical Oxidation-Enzymatic Reduction Sequence.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2006Application in Asymmetric Catalysis Abstract Enantiomerically pure 4-(dimethylamino)-3-(1-hydroxyalkyl)pyridines and 4-(dimethylamino)-3-[hydroxy(phenyl)methyl]pyridine have been prepared through efficient chemoenzymatic routes. For this purpose different lipases and oxidoreductases have been tested in the preparation of optically active 4-chloro derivatives and baker's yeast was found to be an excellent catalyst for the bioreductions of the corresponding ketones. Their applications as enantioselective nucleophilic catalysts have been studied, important catalytic properties were observed in the stereoselective construction of quaternary centers. [source] Synthetic Scope and Mechanistic Studies of Ru(OH)x/Al2O3 -Catalyzed Heterogeneous Hydrogen-Transfer ReactionsCHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2005Kazuya Yamaguchi Dr. Abstract Three kinds of hydrogen-transfer reactions, namely racemization of chiral secondary alcohols, reduction of carbonyl compounds to alcohols using 2-propanol as a hydrogen donor, and isomerization of allylic alcohols to saturated ketones, are efficiently promoted by the easily prepared and inexpensive supported ruthenium catalyst Ru(OH)x/Al2O3. A wide variety of substrates, such as aromatic, aliphatic, and heterocyclic alcohols or carbonyl compounds, can be converted into the desired products, under anaerobic conditions, in moderate to excellent yields and without the need for additives such as bases. A larger scale, solvent-free reaction is also demonstrated: the isomerization of 1-octen-3-ol with a substrate/catalyst ratio of 20,000/1 shows a very high turnover frequency (TOF) of 18,400 h,1, with a turnover number (TON) that reaches 17,200. The catalysis for these reactions is intrinsically heterogeneous in nature, and the Ru(OH)x/Al2O3 recovered after the reactions can be reused without appreciable loss of catalytic performance. The reaction mechanism of the present Ru(OH)x/Al2O3 -catalyzed hydrogen-transfer reactions were examined with monodeuterated substrates. After the racemization of (S)-1-deuterio-1-phenylethanol in the presence of acetophenone was complete, the deuterium content at the ,-position of the corresponding racemic alcohol was 91,%, whereas no deuterium was incorporated into the ,-position during the racemization of (S)-1-phenylethanol-OD. These results show that direct carbon-to-carbon hydrogen transfer occurs via a metal monohydride for the racemization of chiral secondary alcohols and reduction of carbonyl compounds to alcohols. For the isomerization, the ,-deuterium of 3-deuterio-1-octen-3-ol was selectively relocated at the ,-position of the corresponding ketones (99,% D at the ,-position), suggesting the involvement of a 1,4-addition of ruthenium monohydride species to the ,,,-unsaturated ketone intermediate. The ruthenium monohydride species and the ,,,-unsaturated ketone would be formed through alcoholate formation/,-elimination. Kinetic studies and kinetic isotope effects show that the RuH bond cleavage (hydride transfer) is included in the rate-determining step. [source] | ||||||||||