Steroids dimethyldioxirane

Dioxiranes, RR C02 [usually 3,3-dimethyldioxirane and 3-(trifluorome-thyl)-3-methyldioxirane], as efficient reagents for oxyfunctionalization of C-H compounds have been described and investigated (see, for example, reviews [46] and recent original publications [47]). Stereoselective hydroxylation of a steroid compound with 3-(trifluoromethyl)-3-methyldioxirane is shown below [47g] ... 

Although less effective than methyl(trifluoromethyl)dioxirane (TFDO), oxyfunctionalization of unactivated methine C-Hs with dimethyldioxirane (DDO) is feasible for various substituted steroids related to the 5/)-cholane and 5a-cholestane series to give novel mono- and dihydroxylated steroids. The reactivity and site selectivity of oxyfunctionalization is affected conspicuously by the structural and steric environments of the target methine carbon atoms. This nonenzymatic procedure may be advantageously applied to selective and short-course s)mtheses of bioactive steroids. Thus, the major reaction product of methyl... 

---