Oxyfunctionalization of unactivated methine carbon atoms with dimethyldioxirane (DMDO) is studied for various substituted steroids related to the 5β-cholane and 5α-cholestane series. A highly efficient, stereoselective, one-step remote oxidation of specific methine carbons is attained by DMDO oxidation under mild conditions to give a variety of novel mono- and dihydroxylated steroids. The reactivity and site selectivity