Synthesis of (S)- and (R)-5-oxo-piperazine-2-carboxylic acid and its application to peptidomimetics.
A straightforward synthesis of (S)- and (R)-N-Boc-5-oxo-piperazine-2-carboxylic acid is reported starting from L- or D-serine and ethyl glyoxylate. Those were evaluated as constituents in two tetrapeptides by studying their secondary structure by (1)H NMR spectroscopy. In the case of Boc-Val-(S)-PCA-Gly-Leu-OMe, two readily interconverting conformations (in a 40%:60% ratio) were observed, differing for the cis-trans isomerizaton of the tertiary amide bond, while Boc-Val-(R)-PCA-Gly-Leu-OMe displayed an equilibrium between a gamma-turn and a type II beta-turn conformation.
Dipartimento di Scienze Chimiche e Ambientali, Università degli Studi dell'Insubria, Via Valleggio, 11, 22100 Como, Italy.
Karine
K
Guitot
Stefano
S
Carboni
Oliver
O
Reiser
Umberto
U
Piarulli
D002264:Carboxylic Acids / Q000138:chemical synthesis*; D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D018716:Molecular Mimicry; D010455:Peptides / Q000138:chemical synthesis*; D010879:Piperazines / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet
D002264:Carboxylic Acids; D010455:Peptides; D010879:Piperazines