Highly potent 2-methylene analogs of 1α,25-dihydroxyvitamin D3: Synthesis and biological evaluation

▸ Starting from quinic acid two syntheses of the A-ring synthon were achieved. ▸ 2-Methylene calcitriol analogs were synthesized by Pd-catalyzed cross-coupling. ▸ Presence of 2-methylene group at C-2 enhances biological activity of calcitriol.