Efficient Synthesis of Functionalized Alkylidenephthalides, Butenolides, Pyranones, and Isocoumarins via I₂–PPh₃: Synthesis of Thunberginols A and F

Abstract

A simple and efficient synthesis of functionalized alkylidenephthalides, butenolides, pyranones, and isocoumarins were achieved using I2-PPh3-Et3N reagent combination. The products obtained through this methods act as versatile components in organic synthesis, enabling further modifications of functional groups. This method exhibits a wide substrate range, employs straightforward and cost-effective reagents, eliminates the need for acidic, carbodiimides or other coupling agents, and operates at ambient temperature. Moreover, this methodology has been successfully applied to the synthesis of two natural products, Thunberginols (A & F)