Magnesium-catalyzed asymmetric direct aldol addition of ethyl diazoacetate to aromatic, aliphatic, and alpha,beta-unsaturated aldehydes.

Magnesium-catalyzed enantioselective aldol between ethyl diazoacetate and aromatic, aliphatic, and alpha,beta-unsaturated aldehydes affords alpha-diazo-beta-hydroxy-esters in high enantioselectivities. Aldol adducts resulting from this asymmetric transformation are versatile intermediates toward the synthesis of several ester containing chiral building blocks.