(2S)-methyl 2-{(Z)-2-[(S)-2-amino-3-(tritylthio)propanamido]but-2-enamido}-3-methylbutanoate 、
(R)-2-[(R,E)-3-(4-methoxybenzyloxy)-7-(tritylthio)hept-4-enamido]-3-methylbutanoic acid 在
N-羟基-7-氮杂苯并三氮唑 、
N,N-二异丙基乙胺 、 Methanaminium,N-[(dimethylamino)(3H-1,2,3-triazolo[4,5-b]pyridin-3-yloxy)methylene]-N-methyl-, hexafluorophosphate(1-) 作用下,
以
二氯甲烷 为溶剂,
以76%的产率得到(5E,7R,11R,14S,17E,20S)-methyl 17-ethylidene-11,20-diisopropyl-7-(4-methoxybenzyloxy)-9,12,15,18-tetraoxo-1,1,1-triphenyl-14-(tritylthiomethyl)-2-thia-10,13,16,19-tetraazahenicos-5-en-21-oate