2α,3α-dihydroxyolean-12-en-28-oic acid methyl ester 、
4-硝基苯甲酰氯 在
吡啶 作用下,
以
乙醚 为溶剂,
反应 2.0h,
以55 mg的产率得到(4aS,6aS,6bR,8aR,10S,11R,12aR,12bR,14bS)-10-Hydroxy-2,2,6a,6b,9,9,12a-heptamethyl-11-(4-nitro-benzoyloxy)-1,3,4,5,6,6a,6b,7,8,8a,9,10,11,12,12a,12b,13,14b-octadecahydro-2H-picene-4a-carboxylic acid methyl ester