Silver-catalyzed regioselective synthesis of pyrano heterocycles: a versatile route to samoquasine A derivatives.

This study introduces a silver-catalyzed method for the efficient and regioselective synthesis of pyrano heterocycles, utilizing readily available alcohols and water as nucleophiles. The method demonstrates high efficiency, delivering excellent yields and selectivity, and is scalable to gram quantities while maintaining broad functional group tolerance. Notably, the synthesized pyrano[3,4-c]quinolines were successfully transformed into diverse samoquasine A derivatives, underscoring the method's applicability in natural product synthesis. This work represents a significant advancement in pyrano heterocycle synthesis, offering a practical route to valuable compounds with potential applications in pharmaceutical and chemical research.