Allylic Oxidation
Mostrando 1-12 de 13 artigos, teses e dissertações.
-
1. Evaluation of the Oxidation Degradation Process of Biodiesel via 1H NMR Spectroscopy
Biodiesel is a suitable alternative to replace the petro-diesel. The biodiesel is formed by unsaturated esters easily degraded by interferences of oxygen, temperature, contact with metals or contaminants. The aim of this research was to investigate the biodiesel degradation process via 1H nuclear magnetic resonance (NMR) spectroscopy, observing the olefinic,
J. Braz. Chem. Soc.. Publicado em: 2020-08
-
2. APRESENTAÇÃO - História Antiga: Diferentes Perspectivas
Biodiesel is a suitable alternative to replace the petro-diesel. The biodiesel is formed by unsaturated esters easily degraded by interferences of oxygen, temperature, contact with metals or contaminants. The aim of this research was to investigate the biodiesel degradation process via 1H nuclear magnetic resonance (NMR) spectroscopy, observing the olefinic,
Rev. Bras. Hist.. Publicado em: 2020-08
-
3. Mechanism of Hop-Derived Terpenes Oxidation in Beer
Terpenes are the main constituents of hops essentiol oil and contribute to the singular sensory properties of beer. However, terpenes are sensitive to oxidation leading to quality loss during beer aging. Herein, the reactivity of terpenes towards 1-hydroxyethyl radical has been determined employing a competitive kinetic approach using the spin-trap α-(4-pyr
J. Braz. Chem. Soc.. Publicado em: 2015-11
-
4. Oxidação alílica de alcenos catalisada por nanopartículas de óxido de cobalto suportadas / Allylic oxidation of alkenes catalyzed by supported cobalt oxide nanoparticles.
Este trabalho compreende a síntese e caracterização de um novo catalisador magneticamente recuperável de CoO para oxidação alílica de alcenos. O catalisador foi preparado através da deposição de nanopartículas (de tamanho entre 2-3 nm) do metal cataliticamente ativo em nanopartículas de magnetita revestidas por sílica. A natureza magnética do s
Publicado em: 2011
-
5. Studies for chemical transformations in bisabolene sesquiterpene systems / Estudos para transformações quimicas em sistemas sesquiterpenicos do tipo bisabolano
O α-(-)-bisabolol (1) é um sesquiterpeno bisabolano isolado de óleos essenciais de uma grande variedade de plantas, e muito conhecido principalmente por suas atividades farmacológicas. Rotas sintéticas visando a obtenção da (+)-hernandulcina e do acetato do (1S)-1-hidroxi-óxido de bisabolol A, outros sesquiterpenos naturais do tipo bisabolano com
Publicado em: 2007
-
6. Sintese total e enantiosseletiva da aglicona do antibiotico (+)-10-desoximetimicina
This work describes the enantioselective total synthesis of (+)-10-Deoxymethynolide (2c), the aglycon of the 12-membered macrolide antibiotic 10-Deoxymethymycin, through the esterification of the C1-C7 and C8-C13 fragments ((-)-339 and (+)-346, respectively) and macrocyclization of the corresponding vinylic iodide-aldehyde via an intramolecular Nozaki- Hiyam
Publicado em: 1998
-
7. Synthesis of AminoaÃÃcares and Compostos GlicoheterocÃclicos / SÃntese de AminoaÃÃcares e Compostos GlicoheterocÃclicos
In the present work, the synthesis of new 2,3-unsaturaed glycosides, amino and branchedchain amino sugars is reported. Reaction of tri-O-acetyl-D-glucal (20) with five alcohols 72a-e using Ferrierâs method provided 2,3-unsaturatd glycosides 73a-e. Deacetylation of compounds 73a-e followed by allylic oxidation furnished enones 75a-e, which are important prec
Publicado em: 1997
-
8. Novel Allylic Oxidation of α-Cedrene to sec-Cedrenol by a Rhodococcus Strain
A bacterial strain, designated KSM-7358, that can use α-cedrene for growth was isolated. The strain was identified as a member of the genus Rhodococcus and catalyzed the novel allylic oxidation of α-cedrene regiospecifically to produce (R)-10-hydroxycedrene (sec-cedrenol) with a very high yield. α-Curcumene was also produced as a possible metabolite of se
-
9. Oxidation of aliphatic olefins by toluene dioxygenase: enzyme rates and product identification.
Toluene dioxygenase from Pseudomonas putida F1 has been studied extensively with aromatic substrates. The present work examined the toluene dioxygenase-catalyzed oxidation of various halogenated ethenes, propenes, butenes and nonhalogenated cis-2-pentene, an isomeric mix of 2-hexenes, cis-2-heptene, and cis-2-octene as substrates for toluene dioxygenase. Enz
-
10. Characterization of a Pseudomonas putida Allylic Alcohol Dehydrogenase Induced by Growth on 2-Methyl-3-Buten-2-ol
We have been working to develop an enzymatic assay for the alcohol 2-methyl-3-buten-2-ol (232-MB), which is produced and emitted by certain pines. To this end we have isolated the soil bacterium Pseudomonas putida MB-1, which uses 232-MB as a sole carbon source. Strain MB-1 contains inducible 3-methyl-2-buten-1-ol (321-MB) and 3-methyl-2-buten-1-al dehydroge
American Society for Microbiology.
-
11. Direct C-1 hydroxylation of vitamin D compounds: convenient preparation of 1alpha-hydroxyvitamin D3, 1alpha, 25-dihydroxyvitamin D3, and 1alpha-hydroxyvitamin D2.
An efficient procedure for the direct C-1 hydroxylation of vitamin D compounds has been developed. The method involves conversion of vitamin D3 tosylates to 3,5-cyclovitamin D derivatives, allylic oxidation with selenium dioxide, and acid-catalyzed solvolysis to the 1 alpha-hydroxyvitamin D analogs. When applied to vitamin D3,25-hydroxyvitamin D3, and vitami
-
12. Red cell membrane and plasma linoleic acid nitration products: Synthesis, clinical identification, and quantitation
Nitric oxide (NO) and its reactive metabolites mediate the oxidation, nitration, and nitrosation of DNA bases, amino acids, and lipids. Here, we report the structural characterization and quantitation of two allylic nitro derivatives of linoleic acid (LNO2), present as both free and esterified species in human red cell membranes and plasma lipids. The LNO2 i
National Academy of Sciences.