(S)-alpha-methyl,alpha-amino acids: a new stereocontrolled synthesis.
A new and convenient stereocontrolled synthesis of the optically pure (S)-alpha-methyl,alpha-amino acids 6(a-d) that exploits the chiral synthon 1,4-N,N-[(S)-1-phenylethyl]-piperazine-2,5-dione (1) is described. The (S)-1-phenylethyl group, bonded to each of the N-atoms of the 2,5-diketopiperazine, acts as a chiral inductor in the first alkylation, while the steric hindrance appears to be the determining factor of stereocontrol in third and forth alkylation.
Dipartimento di Chimica G.Ciamician, Università di Bologna, Via Selmi 2, 40126 Bologna, Italy. daniele.balducci4@unibo.it
Daniele
D
Balducci
Ilaria
I
Lazzari
Magda
M
Monari
Fabio
F
Piccinelli
Gianni
G
Porzi
D000409:Alanine / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry; D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry*; D000613:Aminobutyrates / Q000138:chemical synthesis / Q000737:chemistry; D018360:Crystallography, X-Ray; D054659:Diketopiperazines / Q000138:chemical synthesis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D013237:Stereoisomerism; D014633:Valine / Q000138:chemical synthesis / Q000737:chemistry
C550458:1,4-N,N-(phenylethyl)piperazine-2,5-dione; D000596:Amino Acids; D000613:Aminobutyrates; D054659:Diketopiperazines; C032737:isovaline; C014328:2-amino-4-phenylbutyric acid; D014633:Valine; D000409:Alanine