Lactic Acid: A New Application as an Efficient Catalyst for the Green One-Pot Synthesis of 2-Hydroxy-12-aryl-8, 9, 10, 12-Tetrahydrobenzo[a]xanthene-11-one and 12-Aryl-8,9,10,12Tetrahydrobenzo[a]xanthen-11-one Analogs

An efficient and benign protocol leading to the synthesis of benzoxanthene derivatives using a multicomponent reaction consisting of aromatic aldehydes, dimedone and 2,7-dihydroxynaphthalene or beta-naphthol in the presence of lactic acid as an efficient, inexpensive and green catalyst under solvent-free conditions is reported. Operational simplicity, good yields, short reaction time, moderate and eco-friendly conditions, and no need for column chromatography make this present methodology more innovative than existing ones.