thiourea and lycorine

A concise and stereoselective construction of the tetracyclic core of lycorine-type alkaloids and the formal synthesis of α-lycorane has been achieved. The feature of the current method is the employment of a bifunctional thiourea-catalyzed cascade reaction as a powerful tool to construct the skeleton of the natural product, which is a challenging yet very rarely explored strategy. As a result, the tetracyclic core is efficiently synthesized in just three simple operations involving two consecutive cascade reactions.

Topics: Amaryllidaceae Alkaloids; Catalysis; Crystallography, X-Ray; Cyclization; Molecular Structure; Phenanthridines; Thiourea