Homogeneous and heterogeneous catalytic asymmetric reactions II. Asymmetric hydrogenation of steroid ketones

Article abstract of DOI:10.1016/0022-328X(89)85065-X

The asymmetric reduction of steroid 17- and 20-ketones with chiral hydrosilanerhodium-(+)-and (-)-diop-complex catalysts allows different stereoselectivities in the formation of 17-alcohols, but not of 20-alcohols.The degree of this stereoselectivity is higher than that attained with other methods.The stereoselectivity can be explained in terms of the most preferred conformation of the α-siloxysteroid-rhodium intermediate complexes.