First synthesis of separable isomeric testosterone dimers showing differential activities on prostate cancer cells.

The synthesis of two separable isomeric testosterone dimers is reported. The dimers are made from testosterone in a 5 step sequence and with 36% overall yield. The key dimerization step was performed using Hoveyda-Grubb's metathesis catalysts on 7alpha-allyltestosterone with 75% yield. The synthesis led to separable isomeric dimers (trans and cis, 2:1). X-ray diffraction crystallography, performed on monocrystal of the minor isomer, confirms the cis geometry of the double bound between the two testosterone units. MTT assays showed that the cis dimer has the highest activity against prostate cancer cell lines. The novel cis dimer is more active than the antiandrogen cyproterone acetate indicating the possible therapeutic value of this molecule.