Abstract: A process for the preparation of 16,17 acetals of pregnane derivatives by trans-ketalization of 16,17-acetonides is described.In the instance of the preparation of 16.alpha.,17.alpha.-butylidenedioxy-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 the known methods.New 16,17 acetals of pregnane derivatives, which can be prepared by the method of the invention, are also described.
May 30, 1985
Date of Patent:
September 22, 1987
Sicor Societa Italiana Corticosteroidi S.p.A.