Aldolases are powerful C−C bond-forming enzymes with high stereoselectivity and broad substrate scope in biocatalysis, but their ability to stereoselectively construct tertiary alcohols has not been fully explored. Herein, we demonstrate that vicinal diones and α-keto esters are electrophiles that can be accepted by both natural and computationally designed aldolases via various catalytic mechanisms. This method allows for the efficient asymmetric synthesis of small molecules with tertiary alcohols, including noncanonical amino acids. This study presents the first types of generic nonnatural substrates of aldolases and reveals new opportunities for the use of aldolases in the synthesis of versatile chiral synthons.