(S)-2-((2S,3S)-2-Amino-3-methyl-pentanoylamino)-propionic acid benzyl ester 、
(S)-4-[(S)-2-((2S,3R)-3-Benzyloxy-2-tert-butoxycarbonylamino-butyrylamino)-propionylamino]-4-[(S)-1-(carboxymethyl-carbamoyl)-3-methyl-butylcarbamoyl]-butyric acid benzyl ester 在
1-羟基苯并三唑 、
N,N'-二环己基碳二亚胺 作用下,
以
二氯甲烷 、
N,N-二甲基甲酰胺 为溶剂,
生成 (S)-4-[(S)-2-((2S,3R)-3-Benzyloxy-2-tert-butoxycarbonylamino-butyrylamino)-propionylamino]-4-[(S)-1-({[(1S,2S)-1-((S)-1-benzyloxycarbonyl-ethylcarbamoyl)-2-methyl-butylcarbamoyl]-methyl}-carbamoyl)-3-methyl-butylcarbamoyl]-butyric acid benzyl ester