New Dipeptides Containing Thiazolidine-4-carboxylic Acid Derivatives: Synthesis and Characterization Using NMR Techniques and X-Ray Data.
作者:Nadia PELLEGRINI、Bernard REFOUVELET、Gregorio CRINI、Olivier BLACQUE、Marek M. KUBICKI、Jean-Francois ROBERT
DOI:10.1248/cpb.47.950
日期:——
New dipeptides, structural analogues of known immunomodulating agents, were prepared by stereospecific condensation between 2-substituted thiazolidine-4-carboxylate esters with N-substituted L-proline or L-thiaproline. The structure of these compounds has been elucidated by combination of NMR methods and X-ray analysis. In addition, NMR measurements on dipeptides indicated the presence of S-cis and S-trans conformers around the amide bonds.
Thiazolidine-2,4-dicarboxylic acid 2 was obtained as a diastereoisomeric mixture from the condensation of glyoxylic acid with L(-)R-cysteine 1. In solution behaviour studies suggested that the reaction proceeded through an acid catalyzed epimerization mechanism. The methyl esterification of 2 was stereoselective, which can be explained by an interconversion of 2a via a ring seco intermediate. Condensation
Synthesis and stereochemical studies of 2-substituted thiazolidine-4-carboxamide derivatives
作者:Bernard Refouvelet、Nadia Pellegrini、Jean-François Robert、Gregorio Crini、Olivier Blacque、Marek M. Kubicki
DOI:10.1002/jhet.5570370604
日期:2000.11
A series of new2-substituted thiazolidine-4-carboxamide derivatives which have potentially useful immunological properties, have been synthesized in a stereoselective manner by coupling 2-subsituted thiazolidine-4-carboxylicacids with amines or amino esters. The structure of these compounds was established by combination of NMR methods and by X-ray analysis.