A process for the epoxidation of olefinic compounds comprising reacting said compounds with hydrogen peroxide introduced as such or produced by substances under the reaction conditions, in the presence of synthetic zeolites containing titanium atoms corresponding to the general formula:
wherein x is in the range of from about 0.0001 to about 0.04, and optionally, in presence of one or more solvents, at a temperature in the range of from about 0 to about 150°C. and at a pressure of from about 1 to about 100 atm. The synthetic zeolites are treated with alkaline substances before and/or during their use in the reaction, or alternatively the synthetic zeolites are acid neutralized with a compound such as X-Si-(R) 3 where X is selected from Cl, Br, I, CH 3 CON-Si-(CH 3 ) 3 , CF 3 COON-Si-(CH 3 ) 3 , (R) 3 -Si-NH, and an imidazolyl group wherein R is selected from an alkyl, aryl or alkylaryl group.