Acetic acid (3S,5S,8R,9S,10S,13S,14S,16R,17S)-16,17-dihydroxy-10,13-dimethyl-17-{(S)-1-[2-(3-methyl-butyl)-[1,3]dioxolan-2-yl]-ethyl}-hexadecahydro-cyclopenta[a]phenanthren-3-yl ester 在
吡啶 、
chromium(VI) oxide 作用下,
以90%的产率得到Acetic acid (3S,5S,8R,9S,10S,13S,14S,17S)-17-hydroxy-10,13-dimethyl-17-{(S)-1-[2-(3-methyl-butyl)-[1,3]dioxolan-2-yl]-ethyl}-16-oxo-hexadecahydro-cyclopenta[a]phenanthren-3-yl ester