Organocatalytic asymmetric hydroxylation of β-keto esters:: Metal-free synthesis of optically active anti-diols

The organocatalytic alpha-hydroxylation of beta-keto esters using cinchona- alkaloid derivatives as the catalyst and peroxides as the terminal oxidant has been investigated and is shown to proceed in high yields and with good enantioselectivity. The scope of the reaction is demonstrated for various substrates, and furthermore, the preparation of optically active anti-diols is presented.