Copper-Catalysed One-Pot Synthesis of 2,3,4,9-Tetrahydro-1 H -Xanthen-1-Ones from 2-Halobenzylbromides and Cyclic-1,3-Diketones in Water

A simple, environmentally friendly, tandem C-benzylation and intramolecular O-arylation for the sequential one-pot synthesis of functionalised 4 H -chromenes is reported. The reactions between 2 -halobenzylbromides and cyclic-1,3-diketones were catalysed by CuO/oxalohydrazide/hexane-2,5-dione in water to produce 2,3,4,9-tetrahydro-1 H -xanthen-1-ones in moderate to high yields. Graphical Abstract A simple, environmental friendly, tandem C-benzylation and intramolecular O -arylation for the sequential one-pot synthesis of 2,3,4,9-tetrahydro-1 H -xanthen-1-ones in water is described.