A Selective Protection of 2,3-Diaminopropionic Acid

Abstract
A two step selective protection of 2,3-diaminopropionic acid yields the useful diaminopropionic acid methyl ester 3a. Further manipulation yields 2(S)-(N-benzyloxycarbonylamino)-3-aminopropionic acid methyl ester hydrochloride 5 in >99.9%ee.