ISSN:
1438-2199
Keywords:
Amino acids
;
bis-lactim ether method
;
13C-isotope
;
(2R)-[5-13C]-3,6-diethoxy-2,5-dihydro-2-isopropylpyrazine
;
L-α-aminoadipic acid
;
NMR spectroscopy
;
Mass spectrometry
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary [2-13C]-L-lysine, [3,4-13C2]-L-lysine and [5,6-13C2]-L-lysine are prepared from simple, commercially available, highly enriched starting materials as [2-13C]-glycine, ethyl [1,2-13C2]-bromo acetate, and [1,2-13C2]-acetonitrile. The introduction of the chiral center is based on a general method starting from the bis-lactim ether of cyclo-(D-Val-Gly). The synthesis of (2R)-[5-13C]-3,6-diethoxy-2,5-dihydro-2-isopropylpyrazine is described. The availability of our method for the preparation of specifically enriched bis-lactim ethers allows the synthesis of a great variety of site specific isotopically labelled (L- and D-)α-amino acids. Moreover, intermediate 4-[(2R,5S)-3,6-diethoxy-2,5-dihydro-2-isopropyl-5-pyrazinyl]butyronitrile is a valuable precursor in the synthesis of L-α-aminoadipic acid. The synthetic scheme in this publication makes both L-lysine and L-α-aminoadipic acid13C- or15N-labelled at any position, easily available. The isotopomers of lysine are obtained on a preparative scale in good yields, with 99%13C and high enantiomeric purity (〉97% e.e.). Three isotopomers are characterized using various spectroscopic techniques,e.g.,1H NMR,13C NMR and Mass spectrometry.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00806490
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