OSW Saponins: Facile Synthesis toward a New Type of Structures with Potent Antitumor Activities
作者:Bingfeng Shi、Pingping Tang、Xiaoyi Hu、Jun O. Liu、Biao Yu
DOI:10.1021/jo051536b
日期:2005.12.1
the 23-N-analogues). Cross metathesis (CM) reaction was also found feasible for modification at the final stage from C22-allyl ester 70. Valuable structure−activity relationships (SAR), together with the practical synthetic approach, have thus been provided to set a new stage for further studies on this new type of antitumor structures.
OSW皂苷,设有16β,17α-dihydroxycholest-22酮糖苷配基和酰化β- d -xylopyranosyl-(1→3)-α-升最近从一组百合植物中发现了附着在16-羟基上的-arabinopyranosyl残基,它们显示出有效的抗肿瘤活性并具有新颖的作用机理。本文描述了一种醇醛醇方法,其由16α-羟基-5-雄烯基17-酮和丙酸酯立体选择性地构建16α,17α-二羟基胆甾22-酮结构。已经探索并完成了向OSW-1的醛醇加合物的精制,包括安装异戊基酮侧链,反转16-羟基构型和选择性保护C22-氧基。特别地,发现该途径对于合成具有C22-酯侧链的OSW皂苷类似物是方便的。因此,OSW-1的23-氧杂类似物(40从工业脱氢异雄甾酮(1)开始,以线性八步顺序制备,总产率为26%。制备具有各种修饰的侧链的类似物,通过醛醇缩合反应用不同长度的丙酸盐,硫代丙酸酯,和乙酸(其制备的68 -