Use of hydroxylamines, hydroxamic acids, oximes and amines as nucleophiles in the Zbiral oxidative deamination of N-acetyl neuraminic acid. Isolation and characterization of novel mono- and disubstitution products. (April 2020)

• Record Type: Journal Article
• Authors: Hawsawi, Mohammed; Pirrone, Michael G.; Wickramasinghe, Anura; Crich, David
• Is Part Of: Carbohydrate research. Volume 490(2020)
• Publication Date: 2020-04
• Subjects: Carbohydrates -- Periodicals; Chemistry, Organic -- Periodicals; Biochemistry -- Periodicals; Carbohydrates -- Periodicals; Chimie organique -- Périodiques; Glucides -- Périodiques; Biochemistry; Carbohydrates; Chemistry, Organic; Periodicals; Electronic journals; 507.78
• DOI: 10.1016/j.carres.2020.107921
• Languages: English
• ISSNs: 0008-6215

Abstract

Abstract: The oxidative deamination of N -nitroso N -acetylneuraminic acid (NeuAc) derivatives is a useful reaction for the formation of 5-desamino-5-hydroxy NeuAc derivatives and their stereoisomers. We demonstrated previously that replacement of the classical nucleophile in these reactions, acetic acid, by phenols resulted in a novel double displacement process with substitution of the acetoxy group at the 4-position taking place in addition to that of the 5-acetamido group, for which we postulated a mechanism centered on the formation of a highly reactive vinyl diazonium ion. We now extend these studies to encompass the use of hydroxylamine-based systems and weakly basic amines as nucleophile. We find that the nature of the product depends significantly on the p K a of the nucleophile, with the more acidic species typically affording only substitution at the 5-position, while the less acidic species give mixtures of elimination products and disubstitution products. The use of aniline as nucleophile is of particular note as it affords a novel aziridine spanning positions 4- and 5- of the neuraminic acid skeleton. Graphical abstract: Image 1 Highlights: Oxidative Deamination. Double substitution. Aziridine formation.