Frank Wüst

Synthesis of “3+1” mixed-ligand oxorhenium(V) complexes containing modified 3,17β-estradiol

Abstract Two rhenium “3+1” mixed-ligand complexes bearing an estradiol moiety were prepared. The small-sized rhenium chelate units were introduced by two different rhenium precursors to give stable complexes in satisfactory yields.

Synthesis of rhenium(I) and technetium(I) carbonyl/dithioether ligand complexes bearing 3,17β-estradiol

Abstract Tricarbonyldithioethermetal(I) complexes of rhenium and technetium with a pendant 3,17β-estradiol have been synthesized and characterized. The steroid ligand was bound to the metal centre by the two sulfur atoms of a 4,7-dithiaoct-1-ine spacer.

Synthesis of Oxorhenium(V) Complexes Derived from 7α-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 the synthesis involves the copper-catalysed, α-selective 1,6-Michael addition of a 4-pentenylmagnesium bromide to 6-dehydrotestosterone 17β-acetate. The α-stereoselectivity is governed by the presence of the C-19 methyl group. The absolute configurations of the epimers were investigated by 1H-NMR studies. Further chemical transformations of the 7α-pentenyl spacer introduced the terminal thiol group, needed for complex formation. The complex formation was accomplished by the “3+1” mixed-ligand concept using two different rhenium precursors. The obtained complexes differ with respect to the central donor atom of the tridentate ligand part, namely, S and O.

A new approach for the synthesis of [11C]-labeled fatty acids

The synthesis of ω-[ 11 C], ω-1-[ 11 C] and ω-3-[ 11 C] palmitic acid employing a cross-coupling reaction between a functionalized copper-zinc reagent with [ 11 C]MeI, [1- 11 C]EtI and [1- 11 C]BuI is described. A tert.-butyl-protected ω-iodo fatty acid precursor t BuO 2 C-(CH 2 ) n -I (n = 11, 13, 14) was converted into the corresponding dialkylzinc reagent [ t BuO 2 C-(CH 2 ) n ] 2 Zn which reacts with Me 2 CuI(MgCl) 2 to give a highly reactive copper reagent [ t BuO 2 C-(CH 2 ) n ] 2 CuI(MgCl) 2 Me . 2 Zn as the labeling precursor. The cross-coupling reaction with [ 11 C]MeI, [1- 11 C]EtI and [1- 11 C]BuI provided the protected palmitic acid, specifically labeled with carbon-11 in several positions. The corresponding carbon-13 labeled compounds were synthesized to verify the labeling position. In a typical synthesis with [1- 11 C]EtI starting with 250 mCi of [ 11 C]CO 2 , 14 mCi (6% decay-corrected based on [ 11 C]CO 2 ) of ω-1-[ 11 C]palmitic acid was obtained within 30 minutes after EOB in 88% radiochemical purity prior to purification by HPLC. The general feature of this approach allows the convenient synthesis of palmitic acid specifically labeled in the ω, ω-1 or ω-3 positions by using several [ 11 C]-labeled alkyl iodides ([ 11 C]MeI, [1- 11 C]EtI or [1- 11 C]BuI) in the same cross-coupling protocol.

SYNTHESIS OF 17α-SUBSTITUTED MERCAPTOALKYNYL DERIVATIVES OF 3,17β-ESTRADIOL

Abstract A homologous series of 17α-substituted mercaptoalkynyl estradiols have been prepared by addition of lithium acetylides to TBDMS-protected estrone

Non-standard isotope production and applications at Washington University

The positron emitting radionuclides, oxygen-15, nitrogen-13, carbon-11, and fluorine-18 have been produced at Washington University for many years utilizing two biomedical cyclotrons; a Cyclotron Corporation CS15 and a Japan Steel Works 16/8 cyclotron. In recent years we have become interested in the production of non-standard PET isotopes. We were initially interested in copper-64 production using the 64Ni(p,n)64Cu nuclear reaction, but now apply this technique to other positron emitting copper isotopes, copper-60 and copper-61. Copper-64 is being produced routinely and made available to other institutions. In 1999 over ten Curies of copper-64 were produced, making copper available to thirteen institutions, as well as research groups at Washington University. We are currently developing methods for the routine productions of other PET radioisotopes of interest, these include; bromine-76, bromine-77, iodine-124, gallium-66, and technetium-94m.