access to 11β-(alkynyl)estranes I is described. The synthesis of key intermediate 11β-ethynylestr-4-ene-3,17-dione 8 can be achieved by stereoselective thermodynamically controlled formation of 11β-aldehyde 1, its conversion to vinyl bromide 7 by Wittig reaction and subsequent dehydrobromination. Broad variation of the acetylenic 11β-substitution is possible by nucleophilic substitution as well as transition