Design, Synthesis, Evaluation and Structure of Allenic 1α,25-Dihydroxyvitamin D Analogs with Locked Mobility at C-17.

Vitamin D receptor ligands have potential for the treatment of hyperproliferative diseases and disorders related to the immune system. However, hypercalcemic effects limit their therapeutical uses and call for the development of tissue-selective new analogs. We have designed and synthesized the first examples of 1α,25-dihydroxyvitamin D analogs bearing an allenic unit attached to the D ring to restrict the side-chain conformational mobility.