Synthesis of spirocyclic imines: Key pharmacophores in the shellfish toxins spirolides and gymnodimine

摘要

The efficient synthesis of several spirocyclic imines of similar structure to that present in the shellfish toxins, the spirolides and gymnodimine, is described. The key steps involved double alpha-alkylation of simple lactam starting materials, Grubbs' ring closing metathesis of the resultant bis-alkylated lactams and LiEt3BH reduction of the TEOC protected lactams to imines. [References: 32]