CATALYTIC ASYMMETRIC-SYNTHESIS OF BETA-HYDROXY KETONES BY PALLADIUM-CATALYZED ASYMMETRIC 1,4-DISILYLATION OF ALPHA,BETA-UNSATURATED KETONES

1,4-Disilylation of alpha,beta-unsaturated ketones with 1.1-dichloro-1-phenyl-2,2,2-trimethyldisilane proceeded in the presence of phosphine-palladium catalysts in benzene. High enantioselectivity (up to 92%) was observed in the disilylation with dichloro[(R)-2,2'-bis(diphenylphosphino)- 1,1'-binaphthyl]palladium(II) as a catalyst (0.5 mol %). The disilylation products, 1-(trimethylsilyloxy)-3- (dichlorophenylsilyl)propenes, were readily converted into optically active alpha-unsubstituted or anti alpha-substituted beta-(phenyldimethylsilyl) ketones, the oxidation of which gave the corresponding optically active beta-hydroxy ketones in high yields.