A new class of long-acting hormonal steroid preparation: synthesis of dimeric ethynodiol and nortestosterone, of dimeric and trimeric androgens and of some dimeric combinations of steroids

Dimeric steroid esters containing an estradiol molecule coupled with a molecule of ethynodiol, cortexo lone, or ethinylandrostenediol respectively, were synthesized. The same method was also used for dimerization of ethynodiol, nortestosterone, and testosterone, and for the preparation of a trimeric androgen consisting of two molecules testosterone linked by one molecule 5-androstene-3β, 17β-diol. The method is based upon the direct esteriflcation of steroid alcohols with steroid hemisuccinates in the presence of N,N'-carbonyldiimidazole. The results of preliminary experiments concerning the biological activity of some of these compounds showed a considerable prolongation of hormonal effect as compared to the respective monomer.