Synthesis of γ,δ-Aziridino α-Amino Acid Derivatives and their Stereoselective Ring Transformation to 2-(Aminomethyl)-1-aminocyclopropanecarboxylic Acid Derivatives

1-Benzyl-2-(bromomethyl)aziridine was successfully substituted with protected glycine esters to afford alkyl 3-(N-benzylaziridin-2-yl)-2-aminopropanoates, as constrained heterocyclic diamino acid derivatives, in good isolated yields. These new aziridines proved to be excellent building blocks for ring transformation to the corresponding stereochemically defined 2-(aminomethyl)-1-aminocyclopropanecarboxylic acid derivatives, including methyl esters, piperidyl amides, and free carboxylic acids.