乙酸酐 、
(20 S)-3α-hydroxy-18α, 19α H-urs-12-en-30β-oic acid 以
吡啶 为溶剂,
反应 5.5h,
以120 mg的产率得到(1R,2S,4aR,6aS,6bR,8aR,10R,12aR,12bR,14bS)-10-Acetoxy-1,4a,6a,6b,9,9,12a-heptamethyl-1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,10,11,12,12a,12b,13,14b-icosahydro-picene-2-carboxylic acid