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Nuclear magnetic resonance spectroscopy nitrogen-15—hydrogen coupling constants in oximes

✍ Scribed by John E. Oatis Jr.; Harry P. Schultz

Publisher
John Wiley and Sons
Year
1978
Tongue
English
Weight
198 KB
Volume
11
Category
Article
ISSN
0749-1581

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✦ Synopsis

Nitrogen-15-hydrogen coupling constants between "N-labeled oximes and a-C-protons, "J(l"NH), of two series of E/Z ketoximes were studied in CCl,, CDCI,, CF,COOH, and DMSO-4. 15N-substituted-methyl phenyl ketoximes constituted the first series and 15N-substituted-methyl 2-quinoxalinyl ketoximes the second series studied. Substituents in the first group were H, Me, f-Bu, NMe,, OMe, C1, Br and I; in the second they were H, NEt,, and C1. / 3 J ( 1 5 ~) l values for the isomers wherein the aliphatic substituent was anti to the oximino hydroxy group were always larger then those for the syn related isomers, permitting assignment of oxime stereochemistry to even a lone oxime diastereomer. Additionally, geminal nitrogen-15-hydrogen coupling, 'J("NH) effects were observed in some compounds.

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