Highly efficient selective monohydrolysis of dialkyl malonates and their derivatives

The highly efficient selective monohydrolysis of symmetric diesters has been applied to monohydrolysis of several dialkyl malonates and their derivatives. The best conditions apply 0.8–1.2 equiv of aqueous KOH with a co-solvent, THF or acetonitrile, at 0 °C. The procedure is highly practical, yielding the corresponding half-esters in high yields in a straightforward manner, without inducing decarboxylation. It was found that the selectivity tends to become higher with increased hydrophobicity.