Pd(0)-Catalyzed-Mediated Synthesis of Vitamin D Compounds

1 alpha,25-Dihydroxyvitamin D3 (1,25D3), the hormonally active form of vitamin D3, regulates mineral homeostasis, cell growth, cell differentiation-proliferation, apoptosis, and immune responses. 1,25D3 activates more than 229 genes associated with several diseases, including arthritis, diabetes and cancer, suggesting its implications in a broader range of biological functions than originally thought. Despite the wide range of biological activities, the clinical applications of 1,25D3 have been limited due to its collateral hypercalcemic effects. This problem has boosted intense synthetic activity in the vitamin D area in the last decades aimed at the development of highly active and non-calcemic analogs for treatment of hyperproliferative diseases. This review covers the most useful synthetic approaches to 1,25D3 analogs containing the natural vitamin D triene system with emphasis on the Pd(0)-catalyzed transformations involved in the formation of the vitamin D triene system and A-ring synthons. image