上游原料
(5S,8R,9S,10S,13S,14S,17S)-10,13-dimethyl-17-(2-methyl-1,3-dioxolan-2-yl)hexadecahydro-3H-cyclopenta[a]phenanthren-3-one (3R,5S,8R,9S,10S,13S,14S,17S)-3,10,13-trimethyl-17-(2-methyl-1,3-dioxolan-2-yl)hexadecahydro-1H-cyclopenta[a]phenanthren-3-ol(5S,8R,9S,10S,13S,14S,17S)-17-acetyl-10,13-dimethylhexadecahydro-3H-cyclopenta[a]phenanthren-3-one
