The first synthesis of the title compound 4, a novel analog of 1α-hydroxyvitamin D (α-calcidiol) that might be therapeutically useful, is described. A key feature in the synthesis is the radical deoxygenation of the diol 21, which was prepared according to the previously reported procedure starting from 17. The resulting deoxygenated product 22 with the desired side-chain moiety was finally led to 4 in a conventional manner. Some aspects of the unusual reactivity of 25-OH on radical deoxygenation are also discussed.
                                    本文描述了标题化合物 4 的首次合成过程,该化合物是 1α- 羟基
维生素 D(α-
钙二醇)的一种新型类似物,可能具有治疗作用。合成过程中的一个关键特征是二元醇 21 的自由基脱氧。最后,以传统方式将得到的具有所需侧链分子的脱氧产物 22 转化为 4。此外,还讨论了 25-OH 在自由基脱氧过程中不寻常反应的一些方面。