Lithium [11C]methyl(2-thienyl)cuprate·LiCN in 1,4-additions to α,β-unsaturated ketones. 11C and 13C labelling of the androgen mesterolone

Abstract

Conjugate 1,4-addition of the [11C]methyl group to α,β-unsaturated ketones was achieved by the use of lithium [11C]methyl(2-thienyl)cuprate · LiCN in a mixture of tetrahydrofuran and diethylether. The 11C labelling procedure was applied successfully to three model compounds and the androgen mesterolone. Mesterolone labelling was also performed with 13C in order to confirm the position of the label. The labelled products were obtained in radiochemical yields of 31–50% within 35–51 minutes of the end of radionuclide production. In a typical synthesis, 1.5 GBq [1α-methyl-11C]mesterolone was synthesized starting from an 18 μA · h cyclotron irradiation. © 1998 John Wiley & Sons, Ltd.