Synthesis of difluorinated β- and γ-amino acids: Investigation of a challenging deoxyfluorination reaction

Backbone-homologated amino acids containing the vicinal difluoride motif have been synthesised in a highly stereoselective manner. The key synthetic transformation is the DeoxoFluor®-mediated fluorination of a vicinal fluorohydrin. The synthetic route is amenable to the production of all possible stereoisomers of α,β-difluoro-γ-aminobutyric acid. In addition, a novel difluoromethyl-substituted β-amino acid is accessed via an unexpected rearrangement process.