A New and Facile Method for the Direct Preparation of α-Hydroxycarboxylic Acid Esters from α,β-Unsaturated Carboxylic Acid Esters with Molecular Oxygen and Phenylsilane Catalyzed by Bis(dipivaloylmethanato)manganese(II) Complex

Article abstract of DOI:10.1246/cl.1990.1869

In the presence of a catalytic amount of bis(dipivaloylmethanato)manganese(II) complex, the oxygenation of benzyl crotonate with molecular oxygen and phenylsilane proceeds smoothly under a mild condition to give benzyl 2-hydroxybutyrate in high yield.The reaction provides a new and convenient method for the direct preparation of various α-hydroxycarboxylic acid esters starting from α,β-unsaturated carboxylic acid esters.The influence of substituents of olefins on regioselectivity is also studied.