cis-4a-cisoid-4a,4b-trans-4b-3-(tert-butyldimethylsilyloxy)-1,4,4a,4b,5,6,7,8,8a,10,10a-dodecahydro-2,4b-dimethylphenanthrene-10α-ol 在
4-二甲氨基吡啶 、 zinc(II) chloride 作用下,
以
吡啶 、
甲苯 为溶剂,
生成
Acetic acid (4aR,4bS,7R,8aR,9S,10aS)-7-[1,3]dithiolan-2-yl-4a,7-dimethyl-6-oxo-tetradecahydro-phenanthren-9-yl ester