[4-(4-bromo-phenyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl]-ethanoic acid 、
cucurbitacin B 在
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,
以
1,2-二氯乙烷 为溶剂,
以27 %的产率得到(2S,8S,9R,10R,13R,14S,16R,17R)-17-((R,E)-6-acetoxy-2-hydroxy-6-methyl-3-oxohept-4-en-2-yl)-16-hydroxy-4,4,9,13,14-pentamethyl-3,11-dioxo-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-2-yl 2-(4-(4-bromophenyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)acetate