In order to find new ways for the functionalization of the A and B rings of the steroid nucleus, the reaction of 5alpha-androst-2-en-17beta-ol 17-acetate (1), cholesta-2,4-diene (4) and cholesta-4,6-dien-3beta-ol 3-acetate (7) was examined using stoichiometric amounts of ruthenium tetraoxide to yield 1,2-cis diols and/or alpha-hydroxy ketones. The reaction of 5alpha-cholest-2-en-3-ol 3-acetate (9) with ruthenium tetraoxide was also carried out and afforded, apart from an alpha-hydroxy ketone, also a diketone and a seco-dicarboxylic acid. The structures of all new steroids, including stereochemical details, were deduced by analysis of spectral data.