CF3SOCl-Promoted Intramolecular Cyclization of β-Diketones: An Efficient Synthesis of Flavones

Abstract An efficient intramolecular cyclization reaction of β-diketones containing a phenyl group with an ortho-hydroxyl substituent was achieved. Using CF3SOCl as an additive, the reaction took place under transition-metal-free and mild conditions. A series of flavones were synthesized in moderate to excellent yields.