羽扇-20(30)-烯-3beta,23,28-三醇 、
乙酸酐 在
吡啶 作用下,
以39%的产率得到[(1R,3aS,5aR,5bR,7aR,8R,9S,11aR,11bR,13aR,13bR)-9-acetyloxy-3a-(acetyloxymethyl)-5a,5b,8,11a-tetramethyl-1-prop-1-en-2-yl-1,2,3,4,5,6,7,7a,9,10,11,11b,12,13,13a,13b-hexadecahydrocyclopenta[a]chrysen-8-yl]methyl acetate