Rearrangements between Primary Ethanolamides of Carboxylic Acids and the Corresponding Aminoethylesters^*

Identification of the oleic acid ethanolamide (OEA) isomer cis-vaccenic acid ethanolamide (VEA) as a highly abundant 18:1 fatty acid ethanolamide in blood plasma from rats and humans

“…Both molecules have the same mass and show similar fragmentation during ESI-MS/MS analysis so that they have to be separated chromatographically [37]. During synthesis, conversion of the ethanolamide linkage to an ester linkage may occur mainly under acidic conditions, but the reaction is reversible under mildly basic conditions [38]. Therefore, it was necessary for further assessment of product identity to determine the linkage type of the synthesized FEAEs, which was achieved by 1 H-NMR.…”

Towards new formulations for polyacrylamide matrices: N‐acryloylaminoethoxyethanol, a novel monomer combining high hydrophilicity with extreme hydrolytic stability

“…We thus noted the following rule: in order to combine both hydrolytic stability and hydrophilicity, the necessary -OH groups should be at such a distance from the amido bond as to prevent formation (via hydrogen bond with the free -OH group) of 5-, 6-and 7-membered rings closing onto the amido linkage. Such rings, in fact, favor hydrolysis of the amido bond, instead of protecting it, via a mechanism of N, 0-acyl transfer [32]. In addition, in order to lessen the hydrophobicity of the N-substituting alkyl chains, an oxygen atom should be present along these chains, preferably every two carbon atoms.…”

Application of the O-N Intramolecular Acyl Migration Reaction in Medicinal Chemistry

“…-Hydroxyl groups are acylated in -hydroxy--amino acids by the N-O shift under strong acidic conditions through a five-membered ring intermediate, [10][11][12][13][14][15][16][17][18]. The opposite rearrangement has also been reported [19][20][21][22] and named as an O-N intramolecular acyl migration reaction as well as an acyl shift or acyl transfer reaction (Fig. 1).…”