RESUMEN
Based on rich sulfur-involving chemical transformations, a novel spokewise synthetic strategy, a subclass of the collective strategies, has been developed to concisely synthesize four erythrina alkaloids through a single-step transformation from a common synthetic precursor. Moreover, six additional erythrina alkaloids have also been synthesized by subsequent 1-2 steps chemical transformations. The current synthetic approaches provide a valuable platform for collective total syntheses of erythrina alkaloids and pseudo-natural erythrina alkaloids.
RESUMEN
A novel tandem oxidative Ritter reaction/hydration/aldol condensation of α-arylketones with substituted propiolonitriles has been developed. This protocol conveniently affords a wide range of functionalized 3-acyl-3-pyrrolin-2-ones through the efficient construction of four chemical bonds, a C-N bond, a CâC bond, and two CâO bonds, and the formation of one ring bearing an aza-quaternary center, which is ascribed to the strategical introduction of functionalized nitriles to this transformation. A reaction mechanism was proposed based on some control experiments.