SYNTHESIS OF OXORHENIUM(V) COMPLEXES DERIVED FROM 7-ALPHA-FUNCTIONALIZED TESTOSTERONE - FIRST RHENIUM-CONTAINING TESTOSTERONE DERIVATIVES

In an effort to assist in the preparation of metal-containing ligands for the androgen receptor, we have synthesized the first oxorhenium(V) complexes containing a pendant testosterone moiety. The key step in t he synthesis involves the copper-catalysed, alpha-selective 1,6-Michae l addition of a 4-pentenylmagnesium bromide to 6-dehydrotestosterone 1 7 beta-acetate. The alpha-stereoselectivity is governed by the presenc e of the C-19 methyl group. The absolute configurations of the epimers were investigated by H-1-NMR studies. Further chemical transformation s of the 7 alpha-pentenyl spacer introduced the terminal thiol group, needed for complex formation. The complex formation was accomplished b y the ''3+1'' mixed-ligand concept using two different rhenium precurs ors. The obtained complexes differ with respect to the central donor a tom of the tridentate ligand part, namely, S and O.