PhMe, C6H4(Me)(2), NO2C6H4Me, (NO2)(2)C6H3Me, AcC6H4Me and AcNHC6H4Me were oxidized with O-3-contg. gases in Ac2O and H2SO4-contg. liq. phase in presence of Mn(AcO)(2) or MnBr2 catalysts at 298-303 K to resp. benzyl acetates and benzylidene diacetates with high selectivity. Use of KBr in the catalytic system allowed formation of the appropriate benzaldehydes.