在
N-乙基马来酰亚胺 、 N-[(dimethylamino)-3-oxo-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl-methylene]-N-methylmethanaminium hexafluorophosphate 作用下,
以
二氯甲烷 为溶剂,
反应 18.0h,
以70%的产率得到(3R,6S,9R,16S,17S,20R,23R)-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