BCl3 Catalyzed, Solvent Free Protocol for the Synthesis of Dihydropyrano[ 3,2-b] Chromenediones

Solvent free synthesis of dihydropyrano[3,2-b]chromenediones was formulated via multicomponent reactions of kojic acid, dimedone and several substituted aromatic aldehydes catalyzed with BCl3. Reactions progressed efficiently and the corresponding heterocyclic products were obtained in good to high yields within short period. The developed protocol is one of the better and efficient alternative methods for the synthesis of dihydropyrano[3,2-b]chromenediones. The simple reaction procedure, easy separation of products, radially available catalyst are certain benefits of this reported protocol.