RESUMO
beta-N-tert-butyloxycarbonyl-N-carboxyanhydrides are very reactive beta-amino acid derivatives. They react cleanly and smoothly with different nucleophiles like aminoesters, enolates, N-methyl-d-glucamine, amidoximes to afford in good to excellent yields peptides, beta-amino ketocompounds, beta-aminosugars and functionalized disubstituted 1,2,4-oxadiazoles.
Assuntos
Aminoácidos/química , Aminoácidos/síntese química , Anidridos/química , Anidridos/síntese química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
alpha-Heterocyclic alpha-aminoesters were obtained in good yields by reaction of a glycine cation equivalent and different heterocyclic nucleophiles; diastereoselectivity using a carbohydrate (galactopyranose) as N-protecting group was modest.
Assuntos
Aminoácidos/química , Compostos Heterocíclicos/síntese química , Ésteres , Estrutura MolecularRESUMO
A general method has been developed for the synthesis of N-tert-butyloxycarbonyl N-carboxyanhydrides from beta-amino acids using Vilsmeier complex. These beta-UNCA are stable, and the reactivity with different nucleophiles (alcohol, amine, lithium enolate) was studied.
RESUMO
The chemoenzymatic synthesis of new surfactants is reported; they were prepared from unprotected carbohydrates, amino acids, and fatty acids. This study pointed out the factors that govern the possibility to enzymatically bind the carbohydrate to the amino acid.
Assuntos
Aminoácidos/metabolismo , Metabolismo dos Carboidratos , Ácidos Graxos/metabolismo , Lipase/metabolismo , Tensoativos/síntese química , Amidas , Candida/enzimologia , Esterificação , Meglumina/metabolismo , Metilglucosídeos/metabolismo , Mucor/enzimologiaRESUMO
Interest in non-natural amino acids is growing because of their potential biological activity. We describe in this paper, a synthesis of phosphonic analogues of 4-hydroxy proline and 5-hydroxy pipecolic acid.
Assuntos
Hidroxiprolina/análogos & derivados , Hidroxiprolina/síntese química , Organofosfonatos/síntese química , Ácidos Pipecólicos/síntese química , Animais , Ciclização , Hidroxiprolina/química , Estrutura Molecular , Organofosfonatos/química , Ácidos Pipecólicos/química , RatosRESUMO
The synthesis of enantiomerically pure azatyrosine, tribromophenylalanine and trichlorophenylalanine is described, using two methods, diastereoselective alkylation and (or) diastereoselective protonation of chiral enolates.
Assuntos
Fenilalanina/análogos & derivados , Alanina/análogos & derivados , Alanina/síntese química , Cromatografia , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Fenilalanina/síntese química , EstereoisomerismoRESUMO
We report here the synthesis of biheterocyclic alpha-amino acids by 1,3 dipolar cycloaddition of acetylenic compounds on alpha-azido alpha-amino esters.
Assuntos
Aminoácidos/química , Aminoácidos/síntese química , Ésteres/química , Espectroscopia de Ressonância Magnética , Tetrazóis/síntese química , Tetrazóis/química , Triazóis/síntese química , Triazóis/químicaRESUMO
Some of the chemistry of amino acids going on in our laboratory (Laboratoire des Amino acides Peptides et Protéines) is described as well as some mass spectrometry methodology for their characterization particularly on solid supports. Several aspects are presented including: (i) the stereoselective synthesis of natural and unnatural amino acids using 2-hydroxypinan-3-one as chiral auxiliary; (ii) the stereoselective synthesis of natural and unnatural amino acids by deracemization of alpha-amino acids via their ketene derivatives; (iii) the synthesis of alpha-aryl-alpha-amino acids via reaction of organometallics with a glycine cation; (iv) the diastereoselective synthesis of glycosyl-alpha-amino acids; (v) the synthesis of beta-amino acids using alpha-aminopyrrolidinopiperazinediones as chiral templates; (vi) the reactivity of urethane-N-protected N-carboxyanhydrides. To characterize natural and non natural amino acids through their immonium ions by mass spectrometry, some methodology is also described.
Assuntos
Aminoácidos/química , Glicopeptídeos/síntese química , Glicopeptídeos/química , Laboratórios , Biossíntese Peptídica , Peptídeos/química , Proteínas/química , Bases de Schiff/química , EstereoisomerismoRESUMO
Interest in non-natural alpha-amino acids is growing because of their potential biological activity. We describe, in this paper, a synthesis of beta-tetrazolyl alpha-amino esters by action of 5-aryl tetrazoles, 2, on N-benzyloxycarbonyl di-dehydro methylalaninate, 3.
Assuntos
Alanina/análogos & derivados , Aminoácidos/síntese química , Tetrazóis/síntese química , Alanina/síntese química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura MolecularRESUMO
In order to develop new specific glutamate analogues at metabotropic glutamate receptors, Diels-Alder, 1-4 ionic and radical reactions were performed starting from (2S)-4-methyleneglutamic acid. Preliminary pharmacological evaluation by measuring IP accumulation using rat forebrain synaptoneurosomes has shown that (2S)-4-(2-phthalimidoethyl)glutamic acid (3a), (2S)-4-(4-phthalimidobutyl)glutamic acid (3b) and 1-[(S)-2-amino-2-carboxyethyl]-3,4-dimethylcyclohex-3-ene-1-carbox ylic acid (8) presented moderate antagonist activities.
Assuntos
Antagonistas de Aminoácidos Excitatórios/síntese química , Ácido Glutâmico/análogos & derivados , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Animais , Antagonistas de Aminoácidos Excitatórios/farmacologia , Ácido Glutâmico/síntese química , Ácido Glutâmico/farmacologia , Prosencéfalo/citologia , Prosencéfalo/efeitos dos fármacos , Ratos , Sinaptossomos/efeitos dos fármacosRESUMO
A short synthesis of 4-methylene glutamic acid was achieved. Under thermal conditions the corresponding anhydride reacted with 2,3 dimethylbutadiene to afford the corresponding DIELS-ALDER adduct in good yield. L-4-methylene glutamic acid essentially acts on glutamate metabotropic receptors and is as potent as L-Glu in producing IPs.
RESUMO
Enantiomerically pureα-substitutedß-amino acids have been synthesized, the key step being the diastereoselective alkylation of aß-alanine derivative with two chiral handles (1S,2R,5S)-menthyl N-[(1S,2S,5S)-2-hydroxypinan-3-ylidene]ß-alaninate.
RESUMO
The purpose of this study was to examine the conditions of sulfenylation reactions of chiralα-amino esters Schiff bases to protect the chirality in theα-position.
RESUMO
The enantiospecific synthesis of severalα-aminophosphonic esters starting from enantiomerically pure derivatives of phosphonic analogues of homoserine is reported.
RESUMO
The enantioselective synthesis of phosphonic analogue of kainic acid is described.