Alkenes as ketol surrogates-a new approach toward enantiopure acyloins.

[reaction: see text] Enantiopure alpha-hydroxy ketones are important building blocks in organic synthesis. This paper describes the use of cyclic ruthenates for the first catalytic regioselective oxidation of vic-diols to alpha-ketols. The combination of RuCl3/Oxone/NaHCO3 was used in a two-step sequence of asymmetric dihydroxylation and regioselective monooxidation for the synthesis of a broad scope of enantiopure acyloins.