Synthesis of 1α-Hydroxyvitamin D<sub>5</sub> Using a Modified Two Wavelength Photolysis for Vitamin D Formation
作者:Robert M. Moriarty、Dragos Albinescu
DOI:10.1021/jo050853f
日期:2005.9.1
developed as a drug. We report a synthesis for this vitamin D analogue which uses a photochemical method for the B-ring opening, leading to the conjugated triene system. The precursor 7-dehydrositosteryl acetate (4) obtained through a one-pot, five-step procedure, was completely free of the 4,6-diene isomer that usually forms in the 5,7-diene synthesis. The pre-vitamin isomer (11) was generated using a modified
1α-羟基维生素D 5(1)是一种有前途的乳腺癌化学预防剂,正在被开发为药物。我们报告了这种维生素D类似物的合成,该合成物使用光化学方法打开B环,从而导致了共轭三烯系统。通过一锅五步程序获得的前体乙酸7-脱氢甾烷乙酸酯(4)完全不含通常在5,7-二烯合成中形成的4,6-二烯异构体。维生素原前体异构体(11)是使用改良的两波长光解程序生成的,与传统上使用的光解方法相比,该步骤的收率提高了3倍以上。在3-三乙基甲硅烷基-反式上进行1α-羟基化步骤通过c的二氧化硫加合物获得的-维生素D 5(17)为-维生素D 5,总产率为48%。光异构化和脱保护完成了合成。