Synthesis of tetraketones in water and under catalyst-free conditions

A simple, environmentally friendly, tandem Knoevenagel condensation and Michael addition procedure is reported. The reactions between cyclic-13-diketones and a variety of aldehydes were carried out in water to afford tetraketones (64-99%). In this green synthetic protocol, the solvent water itself catalysed the reaction by hydrogen bonding, thus avoiding the use of any other catalysts to make the work up procedure easier.