三氟乙酸 、
(S)-2-[(2S,3R)-3-tert-Butoxycarbonylamino-2-hydroxy-4-(2-methoxy-phenyl)-butyrylamino]-4-methyl-pentanoic acid tert-butyl ester 以78%的产率得到(S)-2-[(2S,3R)-3-Amino-2-hydroxy-4-(2-methoxy-phenyl)-butyrylamino]-4-methyl-pentanoic acid; compound with trifluoro-acetic acid