2,2-二甲基琥珀酸酐 、
(1R,3aS,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bR)-9-hydroxy-N-((S)-1-(4-methoxyphenyl)ethyl)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)icosahydro-3aH-cyclopenta[a]chrysene-3a-carboxamide 在
吡啶 、
4-二甲氨基吡啶 作用下,
反应 18.0h,
以77%的产率得到4-[[(1R,3aS,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bR)-3a-[[(1S)-1-(4-methoxyphenyl)ethyl]carbamoyl]-5a,5b,8,8,11a-pentamethyl-1-prop-1-en-2-yl-1,2,3,4,5,6,7,7a,9,10,11,11b,12,13,13a,13b-hexadecahydrocyclopenta[a]chrysen-9-yl]oxy]-2,2-dimethyl-4-oxobutanoic acid