异三尖杉酯碱类似物-酒石酸甲酯三尖杉碱酯的合成

异三尖杉酯碱系三尖杉属植物中所含具有抗肿瘤活性的四种生物碱之一,其本身的合成已有三种不同的方法^1-3]先后获得成功。但是,在这些合成中,生成的异三尖杉酯碱都是立体异构体的混合物。据报导^4.5]异三尖杉酯碱及其某些类似物对癌细胞具有明显的抑制作用。为了考察这类化合物的结构与抗癌活性之间的关系,并为异三尖杉酯碱立体异构体构型的确定提供依据,我们进行了(2R,3R)-酒石酸甲酯三尖杉碱酯Ⅵ和(2S,3S)-酒石酸甲酯三尖杉碱酯Ⅶ的合成。

Synthesis of Isoharringtonine Analogues-Cephalotaxine Methyl Tartrate

The(2R,3R)or(2S,3S)-Cephalotaxinc methyl tartrate acetonide Ⅳ or Ⅴ was prepared by the monocstcr exchange reaction of(2R,3R)or(2S,3S)-dimethyl tartrate acetonidc Ⅰ or Ⅱ with cephalotaxine Ⅲ under the catalysis of CH₃ONa Compounds Ⅳ andⅤ were hydrolyzed by F₃CCO₂H-H₂O(96:4)to give(2R,3R)and(2S,3S)-cephalotaxine methyl tartrate Ⅵ and Ⅶ,The ester exchange reaction may be employed in the preparation of the other analogues.