Brønsted Acid Catalyzed α-Hydroxylation of β-Dicarbonyl Compounds

Significance

A highly enantioselective Brønsted acid catalyzed α-hydroxylation of β-dicarbonyl compounds is described. Using nitroso compounds as oxygen source, β-keto esters with ester groups of various steric demand were ­hydroxylated in high yields and enantio­selectivity. Additionally, an α-hydroxylation of β-diketones was achieved, although the products were obtained in lower yields and enantioselectivities.