71937-61-6Relevant articles and documents
ASYMMETRIC SYNTHESIS OF AMINO ACIDS BY CATALYTIC REDUCTION OF AZLACTONES OF SUBSTITUTED ACYLAMINOACRYLIC ACIDS. COMMUNICATION 12. AMINOLYSIS OF 4-SEC-BUTYL-5-OXAZOLONES AND MECHANISM OF REDUCTIVE AMINOLYSIS OF 4-SEC-BUTYLIDENE-5-OXAZOLONES
Khatskevich, I. E.,Kalnin', I. K.,Karpeiskaya, E. I.,Klabunovskii, E. I.
, p. 330 - 335 (1983)
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A new method proposed for the determination of absolute configurations of α-amino acids
Gomez, Edison Diaz,Duddeck, Helmut
experimental part, p. 222 - 227 (2010/02/28)
Enantiopure α-amino acids were converted to 4-substituted 2-aryl- and 2-alkyl-5(4H)-oxazolones under partial racemization. These nonracemic mixtures were dissolved in CDCl3, an equimolar amount of the chiral dirhodium complex Rh2(II)[(R)-(+)-MTPA]4 (MTPA-H = Mosher's acid) was added, and the 1H NMR spectra of the resulting samples were recorded [dirhodium method). The relative intensities of 1H signals dispersed by the formation of diastereomeric adducts allow to determine the absolute configuration (AC) of the starting a-amino acids. Binding atoms in the adducts were identified by comparing the 1H and 13C chemical shifts of the oxazolones in the absence and presence of Rh2(II)[(R)-(+)- MTPA]4. Thereby, information about the scope and limits of this method can be extracted. A protocol how to use this method is presented. Copyright
