From beta-N-tert-butyloxycarbonyl N-carboxyanhydrides to beta-aminoacid derivatives.

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.

Synthesis of new alpha-heterocyclic alpha-aminoesters.

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.

Urethane N-carboxyanhydrides from beta-amino acids.

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.

Chemoenzymatic synthesis of surfactants from carbohydrates, amino acids, and fatty acids.

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.

Synthesis of phosphonic analogues of 4-hydroxyproline and 5-hydroxypipecolic acid.

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.

Diastereoselective synthesis of non-proteinogenic alpha-amino acids.

The synthesis of enantiomerically pure azatyrosine, tribromophenylalanine and trichlorophenylalanine is described, using two methods, diastereoselective alkylation and (or) diastereoselective protonation of chiral enolates.

Synthesis of biheterocyclic alpha-amino acids.

We report here the synthesis of biheterocyclic alpha-amino acids by 1,3 dipolar cycloaddition of acetylenic compounds on alpha-azido alpha-amino esters.

Some of the amino acid chemistry going on in the Laboratory of Amino Acids, Peptides and Proteins.

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.

Synthesis of beta-tetrazolyl DL-alanine derivatives.

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.

Synthesis and biological activity of glutamic acid derivatives.

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.

Neuroexcitatory amino acids: 4-methylene glutamic acid derivatives : Short Communication.

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.

Asymmetric synthesis ofα-substitutedß-amino acids using aß-alanine derivative with two chiral handles.

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.

Sulfenylation of chiral Schiff bases.

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.

Asymmetric synthesis ofα-aminophosphonic acids.

The enantiospecific synthesis of severalα-aminophosphonic esters starting from enantiomerically pure derivatives of phosphonic analogues of homoserine is reported.

Neuroexcitatory amino acids: phosphonic analogue of kainic acid.

The enantioselective synthesis of phosphonic analogue of kainic acid is described.