Perfluoroalkylation of Nitrones for the Synthesis of a Series of Fucosidase Inhibitors
Résumé
Fucosidase inhibitors represent captivating targets for various biological applications. Iminosugars featuring a fluoroalkyl chain in the pseudoanomeric position were synthesized by nucleophilic addition of a perfluoroalkyl Grignard reagent to a nitrone. Reduction of the N–O bond of the hydroxylamine was achieved by treatment with an aqueous solution of sulfur dioxide. The pKa = 4.5 of the target pyrrolidine reflected a strong electronic effect of the fluoroalkyl chain. Inhibitory potencies of the fluorinated iminosugars and their corresponding hydroxylamines were evaluated against α-Lfucosidase at various pH values.