Synthesis of β-keto esters by condensing various aldehydes with ethyl diazoacetate is achieved by using molybdenum(VI) dichloride dioxide. Aromatic, aliphatic, and heterocyclic aldehydes are successfully condensed with ethyl diazoacetate to obtain corresponding β-keto esters in high yields at room temperature.
molybdenum - catalyst - β-keto esters - aldehydes - ethyl diazoacetate