Nouveaux éthers des hormones oestrogenes

The invention comprises steroids of the general formula: wherein X represents an a -hydroxy group or a b -hydroxy a -alkyl grouping in which the alkyl group contains 1 to 3 carbon atoms and Y represents hydrogen or a hydroxy group, and the preparation thereof by reacting the corresponding free 3-hydroxy compound or the sodium or potassium salt thereof with a cyclopentyl halide in the presence of a basic condensing agent such as an alkaline hydroxide, carbonate or alcoholate. Pharmaceutical compositions having estrogenic activity contain one or more steroids of the above general formula and a non-toxic pharmaceutical carrier suitable for oral or parenteral administration.