(2R,3S)-2-(tert-butoxycarbonylamino)-3-(tert-butyldimethylsilyloxy)butanoic acid 、 dimethyl (2S,2'S,3aR,3a'R,8aR,8a'R)-6,6'-dichloro-3a,3a'-bis((triethylsilyl)oxy)-1,1',2,2',3,3',3a,3a',8,8',8a,8a'-dodecahydro-5,5'-bipyrrolo[2,3-b]indole-2,2'-dicarboxylate 在
2,3,4-三甲基吡啶 、
N-羟基-7-氮杂苯并三氮唑 、 Methanaminium,N-[(dimethylamino)(3H-1,2,3-triazolo[4,5-b]pyridin-3-yloxy)methylene]-N-methyl-, hexafluorophosphate(1-) 作用下,
以94%的产率得到dimethyl (2S,2'S,3aR,3a'R,8aS,8a'S)-1,1'-bis((2R,3S)-2-((tert-butoxycarbonyl)amino)-3-((tert-butyl(dimethyl)silyl)oxy)butanoyl)-6,6'-dichloro-3a,3a'-bis((triethylsilyl)oxy)-1,1',2,2',3,3',3a,3a',8,8',8a,8a'-dodecahydro-5,5'-bipyrrolo[2,3-b]indole-2,2'-dicarboxylate