Synthesis of Highly Z-Selective Coumarin Annulated Dioxocine, Dioxacindione and Macrocycles Using Grubbs' Second-Generation Catalyst

The diversity-oriented organic synthesis of novel coumarin annulated tricyclic dioxocine, dioxacindione scaffolds with Z-selectivity and the symmetrical pentacyclic coumarin macrocyclic derivatives is demonstrated from substituted hydroxyl coumarins via ring-closing metathesis in the presence of Grubbs' second-generation catalyst as the facile and efficient route with excellent yields. This synthetic strategy provides a route for the intramolecular ring-closing metathesis to access a library of novel tricyclic coumarin heterocycles and pentacyclic coumarin macrocycles having different ring systems.