Short, Efficient Syntheses of the Amaryllidaceae Alkaloids (-)-Amabiline and (-)-Augustamine via Intramolecular 2-Azaallyl Anion Cycloadditions

摘要

The Amaryllidaceae alkaloids continue to be of interest as synthetic targets due to the wide range of biological activities exhibited by these bases. We report exceptionally short and efficient total syntheses of the Amaryllidaceae alkaloids (-)-amabiline (1) and (-)-augustamine (2) (Figure 1), neither of which have been previously synthesized. In addition to providing further evidence of the utility of 2-azaallyl anion cycload-ditions, this work serves to confirm the absolute stereochemistry of these two alkaloids.