A new synthetic pathway for preparing perfluorinated p-alanines is described. 2-Perfluoroalkyl-ethanols are oxidized, dehydro-fluorinated, substituted with an azide group and finally hydrogenated with excellent yields. The C-perfluoroalkylated beta -alanines obtained in this way are subsequently used as hydrophobic moieties for the synthesis of amphiphilic lipo-peptides and lipo-peptidoamines. The choice of the peptidoamine structure is justified by the anti-oxidative and complexing properties of natural analogues such as carcinine and cannosine. Measurements of the surface tension of aqueous solutions of the compounds synthesized reveal their surfactant properties. Potentiometric and spectroscopic investigations give evidence for their good ability to complex copper(II) ions in solution. (C) 2001 Elsevier Science B.V. All rights reserved.
Réaction d'alcoolates sur les 2-perfluoroalkyl-éthanoate d'alkyle
The reaction of alcoholates with esters of perfluoroalkylethanoic acid (I) and 3-perfluoroalkyl-3-fluoro-propenoic acid (II) has been studied. Formation of ethers of the enol ester III or the acetal IV depends on the stoichiometric conditions used. The formation of the products proceeds via a Michael-type addition and elimination of fluoride ions from the enolate formed as an intermediate.