Abstract: The present invention relates to 11?-fluoro-3-acetoxyestra-3,5-dien-17-one as a suitable intermediate in the preparation of 11-fluoro-substituted steroids and to the process for preparation thereof. For this purpose, 11?-hydroxyestra-4-ene-3,17-dione is reacted with 1 to 3 equivalents of n-nonafluorobutanesulfonyl fluoride and 3 to 5 equivalents of diazabicycloundecene (DBU) at ?40 to ?20° C. in an organic aprotic solvent and, after an aqueous workup, reacted with 5 to 10 equivalents of acetic anhydride and 0.01 to 1 equivalent of a strong acid. The desired product precipitates spontaneously out of the reaction solution and is obtained in a very high purity by filtration. The process is notable for the very high yield, avoidance of a chromatographic purification of the product, a reduced proportion of wastes and significantly increased process throughput. The process according to the invention is therefore especially suitable for preparing 11?-fluoro-3-acetoxyestra-3,5-dien-17-one on a large industrial scale.

Abstract: This invention relates to a process for the production of 7&agr;-methyl steroids of general formula I, 1