Chiral Alcohols
Mostrando 13-22 de 22 artigos, teses e dissertações.
-
13. Biorreciclagem de hexano e estudo de reações de óxido-redução usando plantas comestíveis / Biorecycling of hexane and study of oxido-reduction reactions using edible plants
The present work had as main goals the use of enzymatic reactions to degrade laboratory residues and to synthesize chiral alcohols. In the first part, it was carried out a screening of microorganisms and hydrolytic enzymes aiming the biorecycling of hexane from laboratory residues (a mixture of hexane-ethyl acetate). This misture is widely employed to purify
Publicado em: 2008
-
14. Resolução do ()-citronelol e ácido ()-citronélico via esterificação enantiosseletiva catalisada pela lipase de candida antarctica
In this work Candida antarctica lipase (CAL-B) was used in the resolution of the ()-citronellol and ()-citronellic acid, by enantioselective esterification. Chiral terpenic acids and alcohols are excellent building blocks for the preparation of more complex molecules with possible biological activities. The ()-citronellic acid has been used as the base mater
Publicado em: 2007
-
15. Addition of Chiral Allyltrichlorostannanes to Chiral Aldehydes : total syntheseis of (+)-Prelactone B / Adição de aliltriclorestanana quirais a aldeidos quirais : sintese total da (+)-prelactona B
The Lewis-acid mediated reaction of allylsilanes and allylstannanes with aldehydes is a well-known procedure for the preparation of homoallylic alcohols. Chiral allyltrichlorostannanes react with chiral a-methyl, b-alkoxy and syn and anti a-methyl-b-alkoxy aldehydes to give the corresponding homoallylic alcohols with moderate to high 1,4-syn-diastereoselecti
Publicado em: 2006
-
16. Utilização de RMN de ¹H na determinação da configuração absoluta de álcoois
This review reports the determination of absolute configuration of primary and secondary alcohols by ¹H NMR spectroscopy, using the Mosher method. This method consists in the derivatization of an alcohol possessig unknown absolute configuration with one or both enantiomers of an auxiliary reagent. The resulting diastereoisomer spectra are registered and com
Química Nova. Publicado em: 2005-12
-
17. Álcoois quirais: métodos químicos e catalíticos de obtenção por redução assimétrica
The importance of chiral alcohols as starting materials for the production of fine chemicals and as useful chirons for the building of several interesting molecules or natural products is reported. The useful and common methods of asymmetric reduction such as the chemical (with organoboron or organoaluminum reagents) and the catalytic ones (with ruthenium or
Química Nova. Publicado em: 2003-01
-
18. Adição de aliltricloroestananas a aldeidos dipeptidicos
The strategies developed for designing inhibitors active against HIV-1 protease involve the incorporation of a dipeptide isostere that resembles the tetrahedral intermediate for peptide bond hydrolysis. The hydroxy amino acid framework B, where the peptidic linkage of the sequence in A is replaced by a CH(OH)CH2 group, resulted as the core unit of potent inh
Publicado em: 2001
-
19. Sintese quimioenzimatica de (-)- serricornina e (+)- sitofilure
Chiral alcohols are versatile and convenient building blocks in the synthesis of biologically important compounds. Asymmetric reduction of b-keto esters by Baker s yeast (S. cerevisiae) has been widely used to obtain chiral alcohols because of simplicity, cheapness and enantioselectivity. However, the optical purities and the yields of these compounds are of
Publicado em: 1997
-
20. Redução fenilcetonas por fermento de pão imobilizado
We have studied the stereospecific reduction of phenylketones by IMBY (immobilized baker s yeast) that not only gives alcohols with high optical yields but can be reused in further reactions after regeneration of the cofator NADH. The chiral alcohols are valuable intermediates for pharmaceuticals synthesis. We have used chrysotile and montmorillonite as supp
Publicado em: 1992
-
21. Catalytic and Molecular Properties of the Quinohemoprotein Tetrahydrofurfuryl Alcohol Dehydrogenase from Ralstonia eutropha Strain Bo
The quinohemoprotein tetrahydrofurfuryl alcohol dehydrogenase (THFA-DH) from Ralstonia eutropha strain Bo was investigated for its catalytic properties. The apparent kcat/Km and Ki values for several substrates were determined using ferricyanide as an artificial electron acceptor. The highest catalytic efficiency was obtained with n-pentanol exhibiting a kca
American Society for Microbiology.
-
22. Alkylphenol Biotransformations Catalyzed by 4-Ethylphenol Methylenehydroxylase
4-Ethylphenol methylenehydroxylase from Pseudomonas putida JD1 acts by dehydrogenation of its substrate to give a quinone methide, which is then hydrated to an alcohol. It was shown to be active with a range of 4-alkylphenols as substrates. 4-n-Propylphenol, 4-n-butylphenol, chavicol, and 4-hydroxydiphenylmethane were hydroxylated on the methylene group next
American Society for Microbiology.