Synthesis and Ring Opening of Methyl 2-Alkyl-3-(alkyl/aryl)-1-benzoylaziridine-2-carboxylates: Synthesis of Polysubstituted Amino Acids.

A new method for the preparation of 2,2,3-trisubstituted methyl 1-benzoylaziridine-2-carboxylates is reported. These compounds have been obtained starting from α-alkyl β-amino acids by formation of the lithium dianion and reaction with iodine. The aziridines undergo ring expansion or ring opening, depending on the substituents of the aziridine ring and on the reaction conditions. Following these methods, both α-substituted α-hydroxy β-amino acids and α-substituted β-hydroxy α-amino acids have been synthesised.