Ethanolysis of the epimeric androstane 4,5- and 5,6- epoxides catalysed by tetracyanoethylene is reported. In contrast to other reagents, these reactions involve the mild room temperature trans diaxial opening of the epoxides. The stereochemistry of three of the products was established by X-ray crystallography.
The presence of a 3β-acetoxyl and 3β-hydroxyl group has been shown to modify the structures of the products arising from the tetracyanoethylene catalysed methanolysis of the epimeric 4,5-epoxyandrostanes when compared to the unsubstituted epoxyandrostanes.