| 摘要 |
The invention comprises 3b -acetoxy-D-homo-5a -androstan-17-one and the ethylene ketal thereof, 3b -hydroxy-D-homo-5a -androstan-17-one ethylene ketal, 17a -methyl-D-homo -5a -androstane-3b , 17b -diol and the 3-acetate thereof, 17a -methyl-D-homo-5a -androstane-3a , 17b , 18-triol and a process for the preparation of 3-hydroxy-19-nor-pregna- 1,3,5(10)-trien-20-one ethylene ketal or 3-methoxy -19- nor-pregna-1,3,5(10) - trien -20- one ethylene ketal by converting a corresponding 18-aldehyde compound to a hydrazone or a semicarbazone and decomposing it with alkali. If an angular carboxyl compound is employed as the starting material it is reduced to the corresponding aldehyde with lithium aluminium hydride. |
