| 摘要 |
The present invention relates to a process for the preparation of 16,17 acetals of pregnane derivatives by trans-ketalization of 16,17-acetonides. In particular the invention relates to the preparation of 16.alpha.,17.alpha.-butyl-idenedioxy-11.beta.,21-dihydroxypregna-1,4-diene-3,20-dione, a compound having useful therapeutic properties, known also as budesonide. It is possible to obtain the more active epimer with high selectivity and remarkable economic advantages in comparison with known methods. New 16,17 acetals of pregnane derivatives, which can be prepared by the method of the invention, are also described. The compounds of the present invention are used in human therapy.
|
