A highly efficient, stereoselective oxyfunctionalization of unactivated carbons in steroids with dimethyldioxirane

Oxyfunctionalization of unactivated methine carbon atoms with dimethyldioxi rane (DMDO) is studied for various substituted steroids related to the 5 be ta -cholane and 5 alpha -cholestane series. A highly efficient, stereoselec tive, one-step remote oxidation of specific methine carbons is attained by DMDO oxidation under mild conditions to give a variety of novel mono- and d ihydroxylated steroids. The reactivity and site selectivity of remote oxyfu nctionalization is influenced significantly by the structural and steric en vironments as well as by the degree of electron density of the target methi ne carbon atoms in the molecules. The non-enzymatic procedure may be useful ly applied to effective and short-step syntheses of bioactive steroids.