(R)-methyl-4-((1R,3aR,6aS,8S,10aS,13aR)-8-acetoxy-3a,7,7,10a,13a-pentamethyl-4,5,11,12-tetraoxohexadecahydro-1H-benzo[a]cyclopenta[f ][10]annulen-1-yl)pentanoate 在
二苯甲酮 作用下,
以
氘代苯 为溶剂,
反应 3.0h,
以66%的产率得到(R)-methyl-4-((1aS,4S,5aR,8aR,11R,11aR,12aR)-4-acetoxy-12a-hydroxy-1a,5,5,8a,11a-pentamethyl-1,7,8-trioxohexadecahydrobenzo[1,4]cyclobuta[1,2-a]cyclopenta[d][8]-annulen-11-yl) pentanoate