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Configurational assignment of β-phenylaspartic acids in solution by 1H and 13C nuclear magnetic resonance

✍ Scribed by M. Barrelle; C. Gey; C. G. Béguin

Publisher
John Wiley and Sons
Year
1988
Tongue
English
Weight
345 KB
Volume
26
Category
Article
ISSN
0749-1581

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✦ Synopsis

Vicinal 3J(HH) and 3J( 13CH) coupling constants are reported for the two diastereoisomers of p-pbenylaspartic acid at various pH values. A comparison between these coupling constants and those expected from the possible conformations of these molecules allows configurational assignments to be made. In strong acidic medium we observed intermediate values for 3J(HH) for both isomers, for one isomer two intermediate values for 3J(C0-or, H-p) and 3J(C0-fl, Ha), and for the other isomer a very small value for 3J(CO-a, H-p) and an intermediate value for 3J(C0-/?, H-a). The discussion shows that the former has the RR/SS configuration and the latter the RS/SR configuration.

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