Neuroactive metabolites from the bark of
Galbulimima belgraveana
occur in variable distributions among trees and are not easily accessible through chemical synthesis because of elaborate bond networks and dense stereochemistry. Previous syntheses of complex congeners such as himgaline have relied on iterative, stepwise installation of multiple methine stereocenters. We decreased the synthetic burden of himgaline chemical space to nearly one-third of the prior best (7 to 9 versus 19 to 31 steps) by cross-coupling high fraction aromatic building blocks (high F
sp
2) followed by complete, stereoselective reduction to high fraction sp
3
products (high F
sp
3). This short entry into
Galbulimima
alkaloid space should facilitate extensive chemical exploration and biological interrogation.
< p >自< italic > Galbulimima belgraveana < /italic >树皮中的神经活性代谢产物在树木之间的分布变化很大,由于复杂的键网络和密集的立体化学结构,通过化学合成难以获得。以前合成复杂同分异构体如himgaline的方法依赖于多个甲烷立体中心的迭代、逐步安装。我们通过交叉偶联高分数芳香基本块(高F sp < /sub> 2)然后完全、立体选择性地还原为高分数sp 3 < /sup> 产物(高F sp < /sub> 3),将himgaline化学空间的合成负担减少到先前最佳的三分之一左右(从19到31步减少到7到9步)。这种进入< italic > Galbulimima < /italic >生物碱空间的简短方法应该有助于进行广泛的化学探索和生物学研究。< /p>