Efficient Synthesis of Tosyl-aziridine-2-t-butyl Carboxylate

Abstract

Tosyl-aziridine-2-t-butyl carboxylate is easily synthesized from Tos-Ser-O-tBu by use of Mitsunobu conditions.

Aziridine-2-carboxylates are valuable precursors to both α- and β-amino acids, as well as other useful synthetic targets,¹ and various approaches to these compounds have been reported.^2–18 Usually, aziridine-2-carboxylates are formed by cyclization of trityl protected mesylates or tosylates of serine and threonine, as originally described by Okawa et. al.,¹³ or by closely related procedures.^14–16 Recently we developed a versatile synthesis of α, β- diaminopropionic acid analogs from tosyl aziridine-2-t-butyl-carboxylate 1 and needed an efficient method to prepare this precursor.¹⁹