Efficient synthesis of functionalized alkylidenephthalides, butenolides, pyranones, and isocoumarins I-PPh: synthesis of Thunberginols A and F.

A simple and efficient synthesis of functionalized alkylidenephthalides, butenolides, pyranones, and isocoumarins was achieved using I-PPh-EtN reagent combination. The products obtained through this method act as versatile components in organic synthesis, enabling further modifications of functional groups. This method exhibits a wide substrate scope, employs straightforward and cost-effective reagents, eliminates the need for acidic, carbodiimide or other coupling agents, and operates at ambient temperature.