(异)螺甾烷型甾体皂苷元的选择性开环反应研究

Study on the selective ring-opening reaction of(Iso) spirostanol saponins

利用一种全新的甾体皂苷元E/F全开环体系,即室温下,加入催化量的无水AlCl3,以CH3COCl作开环试剂、CH2Cl2作溶剂的开环体系,以良好的收率及选择性实现了甾体工业重要基础原料薯蓣皂苷元、剑麻皂苷元的E/F全开环,提出了可能的开环反应机理.开环产物具有胆甾烷的完整碳骨架并在C16,C22,C26位引入了具有良好衍生能力的多个官能团,该产物为一系列高活性甾体化合物的简捷合成提供了原料.

The highly selective conversion of the side chain in diosgenin and tigogenin into 26-chloro-16β-acetoxy-22-one-framework was achieved in good yields using the new E/F ring-opening system,namely acetyl chloride and CH2Cl2 in the presence of catalytic amount of anhydrous AlCl3.The corresponding ring opened products have been prepared and characterized.Mechanism has been proposed for this new reaction.These ring-opened products were particularly suitable as new starting material for synthesizing bioactive steroids with side chain,because of having the intact skeleton of cholestanol alkanes and several functional groups at the positions of C16,C22 and C26.