乙酸酐 、 (2S,3aR,5aR,10aS,11aR,11bR)-2-Hydroxy-2-((R)-1-hydroxy-ethyl)-1,1-dimethyl-1,2,3,3a,4,5,5a,6,9,10,10a,11,11a,11b-tetradecahydro-cyclopenta[a]anthracen-8-one 在
吡啶 作用下,
生成
DL-3-oxo-7β,15α-ethano-11,12-seco-11,19-bisnorpregn-4-ene-17α,20α-diol 20-acetate