(8S,11R,13S,14S,17S)-17-hydroxy-11-[4-((RS)-1-hydroxyethyl)phenyl]-13-methyl-17-pentafluoroethyl-1,2,6,7,8,11,12,13,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-3-one 、
N-Boc-L-缬氨酸 在
吡啶 、
4-二甲氨基吡啶 、
盐酸-N-乙基-Nˊ-(3-二甲氨基丙基)碳二亚胺 作用下,
反应 16.0h,
以75%的产率得到(S)-2-tert-butoxycarbonylamino-3-methylbutyric acid (RS)-1-[4-((8S,11R,13S,14S,17S)-17-hydroxy-13-methyl-3-oxo-17-pentafluoroethyl-2,3,6,7,8,11,12,13,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-11-yl)phenyl]ethyl ester