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Rotational Barriers and 15N Chemical Shifts of N-Acyl-N-alkyl-substituted Amino Acids

✍ Scribed by Tomonaga Ozawa; Yuichi Isoda; Hiroshi Watanabe; Tomoaki Yuzuri; Hiroko Suezawa; Kazuhisa Sakakibara; Minoru Hirota

Publisher: John Wiley and Sons
Year: 1997
Tongue: English
Weight: 361 KB
Volume: 35
Category: Article
ISSN: 0749-1581
DOI: 10.1002/(sici)1097-458x(199705)35:5<323::aid-omr98>3.0.co;2-5

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✦ Synopsis

Rotational barriers about the CÈN bonds of several N-acyl-N-methyl-a-amino acids and their esters R3COÈ N(R4)ÈCR1R2ÈCOOR5, and also N-Boc-protected dipeptides, were determined and the steric e †ects caused by the substituents R1-R5 are discussed by comparing them with the results of MM3 calculations on these amides. Bulky substituents on both the acyl group and the nitrogen atom were shown to have lower DGt. In the series of N-acylglycines with variable R3, the 15N chemical shifts were correlated with DGt.

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