在
                                                                                                                                                                                 
N-乙基吗啉   、                                                                                                  
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25%的产率得到(3R,6S,9R,16S,17S,20R,23S)-7-Benzyloxy-16-benzyloxycarbonylamino-20-((S)-1-benzyloxy-ethyl)-17-isopropyl-3,4,6-trimethyl-2,5,8,15,19,22-hexaoxo-18-oxa-1,4,7,13,14,21,27-heptaaza-tricyclo[21.4.0.0
9,14]heptacosane-13,27-dicarboxylic acid dibenzyl ester