Synthesis and characterization of chiral N-O turns induced by alpha-aminoxy acids.
Chiral alpha-aminoxy acids of various side chains were synthesized with high optical purity starting from chiral alpha-amino acids. The conformations of diamides 13a-e, 15, and 16 were probed by using NMR, FT-IR, and CD spectroscopic methods as well as X-ray crystallography. The right-handed turns with eight-membered-ring intramolecular hydrogen bonds between adjacent residues (called the N-O turns) were found to be preferred for D-aminoxy acid residues, and they were independent of the side chains. The rigid chiral N-O turns should have great potential in molecular design.
Yang
D
D
Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong. yangdan@hku.hk
Li
B
B
Ng
F F
FF
Yan
Y L
YL
Qu
J
J
Wu
Y D
YD
D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D013057:Spectrum Analysis; D013237:Stereoisomerism
D000596:Amino Acids