New Synthetic Strategies to Vitamin D Analogues Modified at the Side Chain and D Ring. Synthesis of 1α,25-Dihydroxy-16-ene-vitamin D<sub>3</sub> and C-20 Analogues<sup>1</sup>
作者:María de los Angeles Rey、José Antonio Martínez-Pérez、Ana Fernández-Gacio、Koen Halkes、Yagamare Fall、Juan Granja、Antonio Mouriño
DOI:10.1021/jo982393e
日期:1999.4.1
yield of vitamin D analogue 35%, 11-13 steps from ketone 11). In route B, the S(N)2' syn displacement of the carbamate moiety by Li(2)Cu(3)R(5) is carried out on intermediates 12 and 13, both of which bear the vitamin D triene unit (average yield of vitamin D analogue 27%, 13-15 steps from ketone 11). The latter route is particularly attractive as an approach to diverse C-20 vitamin D analogues for biological
已开发出两种有效的合成途径,以合成1α,25-二羟基-16-烯-维生素D(3)(4a)及其C-20类似物(3和4)。路线A和路线B共有的关键特征是引入在C20(17、21、19和25)处官能化的侧链。在途径A中,CD侧链片段5和6是通过Li(2)Cu(3)R(5)对烯丙基氨基甲酸酯8和9(X = OCONHPh)进行S(N)2'顺式置换而制备的。然后通过使用Wittig-Horner方法(维生素D类似物的平均收率35%,距酮11 11-13步)将后一片段与A环片段组装在一起,构建三烯单元。在路线B中,Li(2)Cu(3)R(5)对氨基甲酸酯部分进行S(N)2'顺式置换是在中间体12和13上进行的,它们均带有维生素D三烯单元(平均维生素D类似物的产率为27%,距酮11-13步)。