scalable racemic as well as an asymmetric approach to the key building block for the synthesis of homocamptothecin and derivatives thereof such as the potent anticancer agent diflomotecan (4) are described. In the asymmetric route, the pyridone ring was assembled applying straightforward carbonyl chemistry. The selective generation of the quaternary stereocenter was accomplished by self reproduction of chiral
描述了一种有效且可扩展的外消旋和不对称方法,用于合成高
喜树碱及其衍
生物(如强效抗癌剂二
氟莫替康 (4))的关键构件。在不对称路线中,
吡啶酮环是通过简单的羰基
化学组装而成的。季立体中心的选择性生成是通过从 (S)-2-羟基
丁酸 (22) 开始的手性信息的自我复制来完成的,该信息利用烯丙基部分作为掩蔽的羰基。经过 10 个步骤(两次色谱纯化),以 9.0% 的总产率获得了光学纯 DE 结构单元 (7) (er > 99.95: 0.05)。不对称的“从头
吡啶酮方法”有可能成为二
氟莫替康技术合成的基础。