(3β,20R)-3,20-dihydroxypregn-5-ene-18-thial cyclic 18-(1,2-ethanediyl mercaptal) 、
乙酸酐 在
吡啶 作用下,
以50%的产率得到Acetic acid (3S,8R,9S,10R,13R,14S,17S)-13-[1,3]dithiolan-2-yl-17-((S)-1-hydroxy-ethyl)-10-methyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-yl ester