4-二甲氨基吡啶 、 (1R,3aS,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bR)-9-(2-bromoacetyl)oxy-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]chrysene-3a-carboxylic acid 以
N,N-二甲基乙酰胺 为溶剂,
生成
3β-[2-(4-dimethylaminopyridinio)acetoxy]lup-20-en-28-oic acid bromide