(+/-)-7,7-ethanediyldioxy-4
t-hydroxy-4b-methyl-1-oxo-(4a
r,4b
t,10a
t)-1,2,3,4,4a,4b,5,6,7,8,10,10a-dodecahydro-phenanthrene-2-carbaldehyde 在
1,4-二氧六环 、
硝酸铵 、
丙烯醛 、
三甲胺 作用下,
生成
rac-(15Ξ,18Ξ)-3,3-ethanediyldioxy-15-ethoxy-11β,18;15,18-diepoxy-14,15-seco-androst-5-en-14-one