4-fluorothiophene-3-carbaldehyde 、
6-alpha,9-alpha-二氟-11-beta,16-alpha,17-alpha,21-四羟基孕甾-1,4-二烯-3,20-二酮 在
三氟甲磺酸 、 magnesium sulfate 作用下,
以
乙腈 为溶剂,
以9.9 %的产率得到(2S,6aS,6bR,7S,8aS,8bS,10R,11aR,12aS,12bS)-2,6b-difluoro-10-(4-fluorothiophen-3-yl)-7-hydroxy-8b-(2-hydroxyacetyl)-6a,8a-dimethyl-1,2,6a,6b,7,8,8a,8b,11a,12,12a,12b-dodecahydro-4H-naphtho[2',1':4,5]indeno[1,2-d][1,3]dioxol-4-one