2-((3R,6S,9S,12S)-3,6-dibenzyl-9-(4-(((benzyloxy)carbonyl)amino)butyl)-14-methyl-4,7,10-trioxo-2,5,8,11-tetraazapentadecan-12-yl)oxazole-4-carboxylic acid 在
O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate 、
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-) 、
3-(二乙氧基邻酰氧基)-1,2,3-苯并三嗪-4-酮 作用下,
以
二氯甲烷 、
乙腈 为溶剂,
以8.5%的产率得到benzyl N-[4-[(4R,7S,10S,13S)-4,7-dibenzyl-3-methyl-13-(2-methylpropyl)-2,5,8,11-tetraoxo-15-oxa-3,6,9,12,17-pentazabicyclo[12.2.1]heptadeca-1(16),14(17)-dien-10-yl]butyl]carbamate