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 在
水 、
三氟乙酸 作用下,
以80%的产率得到(S)-2-amino-5-(((3R,5R,8R,9S,10S,13R,14S,17R)-17-((R)-4-carboxybutan-2-yl)-10,13-dimethylhexadecahydro-1H-cyclopenta[a]phenanthren-3-yl)oxy)-5-oxopentanoic acid