2-(4-acetoxyphenyl)-4-methyl valeric acid 、
methyl 4-(2(R)-amino-2(R)-(methoxycarbonyl)ethylthio)-2(S)-(3,3-dimethylbutanoylamino)butyrate 在
(benzotriazo-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate 、
N,N-二异丙基乙胺 作用下,
以
二氯甲烷 、
水 为溶剂,
以63%的产率得到methyl 4-(2(R)-(2(R,S)-(4-acetyloxyphenyl)-4-methylpentanoylamino)-2(R)-(methoxycarbonyl)ethylthio)-2(S)-(3,3-dimethylbutanoylamino)butyrate