A simple three-step procedure converted the readily accessible (2-bromo-1, 1-difluoroethyl) arenes () into α-aryl-α, α-difluoroacetaldehydes (). Subsequent hydrocyanation, hydrolysis, oxidation and again hydrolysis afforded β-aryl-β, β-difluoro-α-oxopropionic acids (). Reductive amination transformed the oxoacids into a separable mixture of α-hydroxyacids and racemic β, β-difluoro-β-phenylalanine derivatives (). Enantiomerically pure β, β- ...
