(5S,8R,9R)-1-Benzyl-10-methyl-8,9-dihydroxy-4,7-dioxo-5-methyl-3,6-diazadecanedicarboxylate 、
(5S,8R,9R)-10-Methyl-8,9-bis(benzoyloxy)-4,7-dioxo-5-methyl-3,6-diazadecanedicarboxylate 在
4-二甲氨基吡啶 、
N,N'-二环己基碳二亚胺 作用下,
以
1,4-二氧六环 为溶剂,
反应 5.0h,
以65%的产率得到Trimethyl(3R,4R,7S,13R,14R,20S,23R,24R)-4,23-bis(benzoyloxy)-14-{[((1S)-2-{[2-(benzyloxy)-2-oxoethyl]amino}-1-methyl-2-oxoethyl)amino]carbonyl}-7,20-dimethyl-1,5,8,11,16,19,22-heptaoxo-1-phenyl-2,12,15,25-tetraoxa-6,9,18,21-tetraazahexacosane-3,13,24...