CD exciton chirality method for determination of the absolute configuration of beta-hydroxy-alpha-amino acid derivatives.
The absolute configuration of beta-hydroxy-alpha-amino acids was studied by CD exciton chirality method using 7-diethylaminocoumarin-3-carboxylate as a red-shifted chromophore. The CD spectra of bischromophoric derivatives of (S)-serine and (2S,3R)-threonine methyl esters (2 and 7) were compared with those of acyclic vic-aminoalcohols and diols (3--6 and 8--9). This study indicates that the polar carboxylate group of beta-hydroxy-alpha-amino acids makes them a unique subclass of vic-aminoalcohols. By combining the data of CD and NMR coupling constants, we are able to correlate their preferred conformer B and positive CD to the corresponding absolute configuration.
Lo
L C
LC
Department of Chemistry, National Taiwan University, Taipei, Taiwan. lclo@mail.ch.nty.edu.tw
Chen
J Y
JY
Yang
C T
CT
Gu
D S
DS
D000596:Amino Acids / Q000737:chemistry*; D002942:Circular Dichroism; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
D000596:Amino Acids