Stereoselective synthesis of optically active alpha-hydroxy ketones and anti-1,2-diols via asymmetric transfer hydrogenation of unsymmetrically substituted 1,2-diketones

[GRAPHICS] A well-defined chiral Ru catalyst RuCl(N-(p-toluenesulfonyl)-1,2-diphenylet hylenediamine)(eta (6)-arene) effectively promotes asymmetric transfer hydr ogenation of 1-aryl-1,2-propanedione with HCOOH/N(C2H5)(3), leading prefere ntially to optically active 1-aryl-2-hydroxy-1-propanone with up to 99% ee and 89% yield at 10 degreesC, The reaction at 40 degreesC gives anti 1-aryl -1,2-propanediol with up to 95% ee and 78% yield, This is a highly efficien t procedure for the synthesis of optically active anti-diols.