tetrabenzyl (3S,8S,11S,16S,21S)-11-amino-8,16-bis(((S)-1,5-bis(benzyloxy)-1,5-dioxopentan-2-yl)carbamoyl)-5,10,14,19-tetraoxo-4,9,15,20-tetraazatricosane-1,3,21,23-tetracarboxylate 、
N-[2-(3,4-bis-benzyloxy-phenyl)-ethyl]-succinamic acid 在
1-羟基苯并三唑 、 O-(1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate 、
N,N-二异丙基乙胺 作用下,
以
N,N-二甲基甲酰胺 为溶剂,
以32.2%的产率得到tetrabenzyl (3S,8S,11S,16S,21S)-8,16-bis(((S)-1,5-bis(benzyloxy)-1,5-dioxopentan-2-yl)carbamoyl)-11-(4-((3,4-bis(benzyloxy)phenethyl)amino)-4-oxobutanamido)-5,10,14,19-tetraoxo-4,9,15,20-tetraazatricosane-1,3,21,23-tetracarboxylate