25-羟基维生素D_3(1)和1α,25-双羟基维生素D_3(2)是维生素D_3(3)在体内的两个重要代谢产物。2是目前所知生理活性最强的维生素D.1和2可治疗软骨病,特别用于对肝脏、肾脏功能不全的维生素D缺乏症。最近日本Kureha公司报道,它们还具有抑制白血病细胞和骨髓肿瘤细胞生长的作用。25-羟基胆固醇(4)是合成1和2的关键中间体。文献已有许多关于它的合成报道。 25-Hydroxy vitamin D 3 (1) and 1α, 25-dihydroxy vitamin D 3 (2) are two important metabolites of vitamin D 3 (3) in the body. 2 is the most physiologically active vitamin D.1 and 2 known to treat rickets, especially for vitamin D deficiency in liver and kidney dysfunction. Recently Kureha reported that they also have the effect of inhibiting the growth of leukemia cells and bone marrow tumor cells. 25-Hydroxycholesterol (4) is a key intermediate for the synthesis of 1 and 2. The literature has many synthetic reports on it.