abstract |
The invention relates to a process for the preparation of 1,4-dehydro-11a-hydroxysteroids of the pregnane series from 1,4-dehydro-11-deoxysteroiden. It is characterized in that the starting materials, which may contain esterified hydroxyl groups, are hydroxylated with Absidia repens under strictly aerobic conditions in a p H range of 4 to 6. |