A General Approach to the Quinolizidine Alkaloids via an Intramolecular Aza-3 + 3 Annulation. Synthesis of (±)-2-Deoxy-Lasubine II

摘要

The first success in constructing a member of quinolizidine family of alkaloids employing an intramolecular aza-[3 + 3] annulation strategy is described here. The key feature is the usage of vinylogous urethane tethered to a vinyl iminium intermediate with trifluoroacetate serving as the counter anion. The proof-of-concept is illustrated with the synthesis of 2-deoxy-lasubine II.