Total Synthesis of (–)-Flueggenine C

Key words

securinega alkaloids - (–)-flueggenine C - Rauhut–Currier reaction - dimerization - Horner–Wadsworth–Emmons reaction

Significance

Jeon and Han report the first total synthesis of the dimeric securinega alkaloid (–)-flueggenine C. The key dimerization step is enabled by a bio-inspired Rauhut–Currier reaction accelerated by the presence of an internal nucleophile. This reaction is pertinent in the biosynthesis of dimeric and oligomeric securinega alkaloids.

Comment

After efficiently synthesizing intermediate C in seven steps and 14% overall yield, the pivotal Rauhut–Currier dimerization and subsequent acetylation provided D in 74% yield. HWE olefination of F afforded unsaturated lactone G. The final ring closure was facilitated by S_N2 displacement of a mesylate culminating at the natural product.