3β,16α,20(R)-trihydroxy-25-acetoxy-2,11,22-trioxocucurbita-5,23(E)-diene 、
乙酸酐 生成 [(3R,8S,9R,10R,13R,14S,16R,17R)-3-acetyloxy-17-[(E,2R)-2,6-diacetyloxy-6-methyl-3-oxohept-4-en-2-yl]-4,4,9,13,14-pentamethyl-2,11-dioxo-3,7,8,10,12,15,16,17-octahydro-1H-cyclopenta[a]phenanthren-16-yl] acetate