Organocatalytic asymmetric β-hydroxylation of α,β- unsaturated ketones

The highly enantioselective organocatalytic β-hydroxylation of α,β-unsaturated ketones was accomplished by using oximes as the oxygen-centered nucleophile. Optically active products are obtained with enantioselectivity up to 94 %. Central to these studies was the use of catalytic primary amine salt A, in which both the cation and the anion are chiral. Amine A exhibits high reactivity and selectivity for iminium-ion catalysis with enones. The potential interest of this novel transformation was demonstrated with the easy conversion of the Michael adducts in enantioenriched anti and syn 1,2-diols without erosion of the optical purity. © Wiley-VCH Verlag GmbH & Co. KGaA, 2007.