Synthesis and biological activity of 25-hydroxy-2-methylene-vitamin D3 compounds

▸ Starting from 1,4-cyclohexanedione monoethylene acetal synthesis of the A-ring synthon was achieved ▸ 2-Methylene vitamin D analogs were synthesized by Pd-catalyzed cross-coupling. ▸ Presence of 2-methylene group at C-2 affected biological activity of vitamin D.