title: Psi[CH2O] pseudodipeptide synthesis. An improved approach which allows absolute configuration determination.
abstract: An improved way to obtain psi[CH2O] pseudodipeptide units is proposed, involving an intramolecular Williamson's reaction, with displacement of bromine by an alkoxide, instead of the classical intermolecular one. Until now, psi[CH2O] pseudodipeptide synthesis done by this new method, has used a protected form of the amino alcohol hydroxyl group to prepare the acyclic precursor. In the present paper, the use of an active ester of the brominated carboxylic acid avoids this protection step. The pseudodipeptides AcGly psi[CH2O]-D,L-Ala-OH and Ac-Ser(Bzl) psi [CH2O]-D,L-Ala-OH were obtained in high yields, through a delta-lactam intermediate, which furthermore allows the determination of the absolute configuration of compounds using HPLC and appropriate nuclear magnetic resonance (NMR) techniques.
authors.affiliation: Department of Endogenous Glycoconjugate and Lectin Biochemistry, University of Orléans, France.
authors.forename: P
authors.initials: P
authors.lastname: Breton
authors.forename: M
authors.initials: M
authors.lastname: Monsigny
authors.forename: R
authors.initials: R
authors.lastname: Mayer
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D004151:Dipeptides / Q000138:chemical synthesis*; D011487:Protein Conformation; D013237:Stereoisomerism
chemical_list: D004151:Dipeptides