(3β,18β,20β)-3-(acetoxy)-20-isocyanato-30-norolean-12-en-11-one 、
苯胺 以
氯仿 为溶剂,
以85%的产率得到Acetic acid (3S,6aR,6bS,8aS,11S,12aR,14bS)-4,4,6a,6b,8a,11,14b-heptamethyl-14-oxo-11-(3-phenyl-ureido)-1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,10,11,12,12a,14,14a,14b-icosahydro-picen-3-yl ester