VERWENDUNG EINES EPOXIDIERUNGS-REAGENZ, SOWIE VERFAHREN ZUR HERSTELLUNG VON 5 ALPHA(10 ALPHA)- EPOXI DELTA 9,11-STEROIDEN

An epoxidation reagent comprising hydrogen peroxide and at least one aryl methyl ketone of the formula I in which X represents a fluorine or chlorine atom, R , R and R , which may be identical or different, each represent a C1-C6-alkyl, C6-C10-aryl, C6-C10-Ar-C1-C6-alkyl, O-C1-C6-alkyl, O-C6-C10-aryl radical, a fluorine, chlorine, bromine or hydrogen atom, a cyano, nitro or trifluoromethyl group, an amido radical -CO-NR R or a sulphonyl radical -SO2R , in which R and R are identical or different and each denote a C1-C6-alkyl, C1-C10-aryl or a C6-C10-aryl-C1-C6-alkyl group, in which in the case of -CO-NR R R and R together can form an aliphatic or aromatic 5- or 6-membered heterocycle, or R and R together represent a fused aliphatic or aromatic ring and its use for the epoxidation of organic compounds are described.