The yohimbinoid alkaloids continue to receive considerable attention from the synthetic community because of their interesting chemical structures and varied biological activity. Although there are several elegant syntheses of certain members of this group of alkaloids, a truly unified approach has yet to be developed. In short, general approaches to this compound class are hampered by a lack of complete control in setting the C(3) stereocentre at a late stage. Herein, we report that a functionalized hydrindanone enables a divergent strategy that builds on existing precedent to address this long-standing challenge. Utilizing an aminonitrile intermediate, the stereochemistry at C(3) of the yohimbinoid skeleton can be controlled effectively in a PictetâSpengler reaction. We applied this approach to the first total syntheses of the C(3) epimeric natural products venenatine and alstovenine. A hydrindanone-based approach to yohimbinoid natural products has been developed. A judicious choice of reaction conditions â inspired by prior work by the Stork group â allows effective control of the stereochemistry at C3 of the yohimbinoid skeleton. This approach has resulted in the first total syntheses of the C3 epimeric natural products venenatine and alstovenine.
由于具有有趣的
化学结构和多样的
生物活性,
育亨宾类
生物碱继续受到合成界的广泛关注。虽然已经对这一类
生物碱的某些成员进行了几种优雅的合成,但尚未开发出真正统一的方法。简而言之,由于在后期阶段无法完全控制C(3)立体中心的形成,因此阻碍了对这一化合物类别的常规方法。在此,我们报告了一种官能化的氢化二
萘酮,它能够基于现有先例,采用一种不同的策略来解决这一长期存在的挑战。利用一种
氨基腈中间体,在Pictet-Spengler反应中可以有效地控制
育亨宾类骨架C(3)处的立体
化学。我们将这种方法应用于C(3)外消旋
天然产物维尼纳丁和阿尔斯托维宁的首次全合成。已经开发出一种基于氢化二
萘酮的
育亨宾类
天然产物的方法。在Stork小组先前工作的启发下,明智地选择反应条件,可以有效地控制
育亨宾类骨架C3处的立体
化学。这种方法已经实现了C3外消旋
天然产物维尼纳丁和阿尔斯托维宁的首次全合成。