(1S,3aS,41R,4a1S,5R,10aR,12aS)-1-(furan-3-yl)-9,10-dihydroxy-4a1,7,7,10a,12a-pentamethyl-3,8-dioxohexadecahydronaphtho[2,1-f]oxireno[2,3-d]isochromen-5-yl acetate 、
2,2-二甲氧基丙烷 在
对甲苯磺酸 作用下,
以
丙酮 为溶剂,
反应 3.0h,
以90%的产率得到(1S,3aS,41R,4a1S,5R,10aR,12aS)-1-(furan-3-yl)-9,10-dihydroxy-4a1,7,7,10a,10,10,12a-heptamethyl-3,8-dioxohexadecahydronaphtho-9,11-dioxol[2,1-f]oxireno[2,3-d]isochromen-5-yl acetate