M. L. Roumestant

Alkylation and protonation of chiral schiff bases: Diastereoselectivity as a function of the nature of reactants

Abstract The factors controlling the diastereoselective alkylation and protonation reactions of chiral Schiff bases prepared from 2-hydroxypinan-3-one and α-aminoesters are reported: nature of the ester, of the alkylating agent and of the base.

Asymmetric synthesis of cis and trans 2-methyl and 2-ethyl 1-amino cyclopropanecarboxylic acids

Abstract A new four step asymmetric synthesis of 2-methyl and 2-ethyl 1-amino cyclopropane carboxylic acids resulted from the cycloaddition of diazomethane to the corresponding chirally derivatized dehydro-aminoacid.

Synthesis of enantiomerically pure phosphonic analogues of homoserine derivatives

Abstract Enantiomerically pure phosphonic analogues of homoserine derivatives are synthesized the key-step being the diastereoselective alkylation of a chiral Schiff base.

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

SummarySome 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 ofα-amino acidsvia their ketene derivatives; (iii) the synthesis ofα-aryl-α-amino acidsvia reaction of organometallics with a glycine cation; (iv) the diastereoselective synthesis of glycosyl-α-amino acids; (v) the synthesis ofβ-amino acids using a-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.

New routes to 1,4- benzodiazepin-2,5-diones

Abstract 1,4-benzodiazepin-2,5-diones have been synthesized in good overall yields by two routes, the first one by cyclisation of dipeptides prepared from Boc anthranilic acid and α-amino acid methyl esters, the second one by reaction of N-carboxy α-amino acid anhydrides with Boc anthranilic acid.

Synthesis of Heterocyclic α-Aminophosphonic Acids

Abstract Heterocyclic α-aminophosphonic acids derivatives were easily obtained by 1,3 dipolar cycloaddition of acetylenic compounds on azido α-aminophosphonic esters.

Rapid solid phase synthesis of α-amino acids

Abstract A solid phase synthetic method for amino acids is developed. The N-acetyl-dehydroalanine is quatitatively bound to Wang resin by the Mitsunobu method. Then a Michael addition is achieved on the double bond with different nucleophiles. Non proteinic N-acetyl-α-amino acids are obtained after cleavage from the resin by mild acid treatment (Scheme 1).

From Oxazolines to Precursors of Aminoacids

Abstract After optimization of the reaction conditions, action of nucleophiles on the tosyl derivatives of 4-hydroxymethyl oxazolines 1 and 2 afforded precursors of α and β aminoacids.

Synthesis ofα-triazolylα-amino acid derivatives

SummaryWe report the synthesis ofα-triazolylα-amino esters by 1,3 dipolar cycloaddition of acetylenic compounds andα-azidoα-amino esters.

Synthesis of enantiomerically pure (3R,4R,5R)-4-hydroxy isoleucine lactone

Abstract A short four-step synthesis of (3 R ,4 R ,5 R )-4-hydroxyisoleucine lactone with total control of stereochemistry is reported, the key intermediate being the didehydroamino acid derivative arising from an aldol dehydration reaction between a glycine anion equivalent and butan-2,3-dione.