3β-tertiobutyldimethylsilyloxy-18-carboxaldehyde-20,20-ethylenedioxy-pregn-5-ene 、
1,2-乙二硫醇 在
三氟化硼乙醚 作用下,
以
二氯甲烷 为溶剂,
反应 3.0h,
以8%的产率得到1-[(3S,8S,9S,10R,13R,14S)-3-(tert-Butyl-dimethyl-silanyloxy)-13-[1,3]dithiolan-2-ylmethyl-10-methyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-17-yl]-ethanone