GaCl3‐Catalyzed [3 + 2]‐Cycloaddition/Esterification Cascade of Donor–Acceptor Cyclopropanes With Salicylaldehydes for the Synthesis of Tetrahydro‐4H‐Furo[3,2‐c]Chromen‐4‐Ones

ABSTRACT A GaCl 3 ‐catalyzed [3 + 2]‐cycloaddition/intramolecular esterification cascade of donor–acceptor cyclopropane‐1,1‐diesters with salicylaldehydes has been reported. A wide range of tetrahydro‐4 H ‐furo[3,2‐ c ]chromen‐4‐ones have been efficiently delivered in moderate to good yields. Mechanistic studies suggest that the reaction involves the [3 + 2]‐cycloaddition followed by intramolecular esterification to access 4 H ‐furo[3,2‐ c ]chromenones.