20190-95-8Relevant articles and documents
cis-trans Isomerism in Monoalkylhydroxamic Acids by 1H, 13C and 15N NMR spectroscopy
Brown, David A.,Glass, William K.,Mageswaran, Rajeswary,Girmay, Berhane
, p. 970 - 973 (1988)
The first example of cis-trans isomerism in monoalkylhydroxamic acids, detected by 1H, 13C and 15N NMR spectroscopy, is reported.The 15N NMR spectrum of CH3CO(15)NHOH gave a clear assignment of the OH and NH protons of both Z and E isomers.The assignment was confirmed by 1H and 13C NMR spectroscopy.A rotational barrier of isomerization (ΔG++c) of 17.8 kcal mol -1 was calculated from the variable-temperature 1H NMR spectra using the method of Shanan-Atidi and Bar-Eli.KEY WORDS cis-trans Isomerism 1H, 13C and 15N NMR Monoalkylhydroxamic acids Rotational barrier
An expeditious hydroxyamidation of carboxylic acids
Ech-Chahad, Abdellah,Minassi, Alberto,Berton, Luca,Appendino, Giovanni
, p. 5113 - 5115 (2007/10/03)
Capitalizing on in situ activation with the cyclic phosphonic anhydride PPAA (1), the conversion of carboxylic acids into hydroxamic acids has been reduced to an experimentally simple one-pot operation that addresses the issue of polyacylation without resorting to a large excess of hydroxylamine or to protection. Scope and selectivity were satisfactory with a wide range of substrates, including α,β-unsaturated acids and hydroxyacids.
