LiOH.H2O/Ultrasonic-Assisted Synthesis of Bisarylmethylidene Derivatives of 2,2-Dimethyl-1,3-Dioxan-5-one System

There is a great current interest in ultrasound assisted organic synthesis because these environmentally benign chemical methodologies are strongly required in light of the paradigm shift to ―Green Chemistry‖. In continuation of our studies to develop environmentally friendly processes[1,2] here we report the synthesis of bis(arylmethylidene)dioxan-5-one derivativesunder environmentally clean LiOH.H2O/ultrasonic conditions.Synthesis of these compounds could provide a pathway to access vicinal tricarbonyl derivatives[3] which are important as coupling reagents for biopolymer conjugates, antibiotic drugs, contact allergen, and photoconductive agents.The α,β diketoester and amide derivatives of these compounds have found synthetic applications in the preparation of various natural products or their precursors such as fusedring β-lactams, indole alkaloids, marine metabolites, enzyme inhibitors, and bioactive depsipeptides[4].The present approach has been carried out by the reaction of 2,2-dimethyl-1,3-dioxan-5-one and aromatic aldehydes in the presence of LiOH. H2O and by using ultrasonic irradiation.A broad scope of aromatic aldehydes was successfully assessed in this work.We believe that the method surpasses limitations that other methodsmay encounter.