Ozonolysis reactions of a series of cyclic olefins 1 in the presence of carbonyl compounds 6 provided the corresponding cross-ozonides 42. Further reactions of ozonides 42 with the independently prepared carbonyloxide +CH2-OO− gave diozonides of structure 43. All of the newozonides have been isolated as pure substances and characterized by their 1H- and 13C-NMR spectra.