5-((3R,5R,8R,9S,10S,13R,14S,17R)-17-((R)-5-(tert-butoxy)-5-oxopentan-2-yl)-10,13-dimethylhexadecahydro-1H-cyclopenta[a]phenanthren-3-yl) 1-(tert-butyl) L-glutamate 、
Fmoc-L-天冬氨酸 beta-叔丁酯 在
1-羟基苯并三唑 、
盐酸-N-乙基-Nˊ-(3-二甲氨基丙基)碳二亚胺 作用下,
以
N,N-二甲基甲酰胺 为溶剂,
以85%的产率得到5-((3R,5R,8R,9S,10S,13R,14S,17R)-17-((R)-5-(tert-butoxy)-5-oxopentan-2-yl)-10,13-dimethylhexadecahydro-1H-cyclopenta[a]phenanthren-3-yl) 1-(tert-butyl) ((S)-2-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-4-(tert-butoxy)-4-oxobutanoyl)-L-glutamate