Base-Promoted Tandem Reaction Involving Insertion into Carbon–Carbon σ-Bonds: Synthesis of Xanthone and Chromone Derivatives

Tandem reactions using base-promoted processes have been developed for the synthesis of xanthone and chromone derivatives. The first examples of base-promoted insertion reactions of isolated carbon–carbon triple bonds into carbon–carbon σ-bonds have been reported. Using these approaches, polycyclic structures can be prepared. This reaction has the potential to become a general synthetic protocol for the preparation of multi-substituted xanthones and chromones due to the abundance of easily accessible starting materials possessing diverse substituent groups.