Three pairs of isomeric 17, 20-epoxy-17-picolyl-derivatives of 5-androstene and 5α- androstane (3–8) have been prepared by an oxidation of 3β-acetoxy-17-picolinylidene- androst-5-ene (2) and 3β-acetoxy-17-picolinylidene-5α-androstane (2) with in situ prepared Cr (VI) oxide-pyridine-complex in methylene chloride at room temperature. X-Ray structural analysis of the suitably crystalline epoxides 5 and 6 revealed the structure of 5 being 17α, ...