乙酸酐 、
(R)-1-[(1S,2S,4aS,4bR,6aR,10aR,10bS,12aR)-1-(2-Hydroxy-ethyl)-2,4b,6a,9,9,10b,12a-heptamethyl-octadecahydro-chrysen-2-yl]-ethanol 在
吡啶 作用下,
生成 Acetic acid (R)-1-[(1S,2S,4aS,4bR,6aR,10aR,10bS,12aR)-1-(2-acetoxy-ethyl)-2,4b,6a,9,9,10b,12a-heptamethyl-octadecahydro-chrysen-2-yl]-ethyl ester