A new route for the synthesis of the title compounds 4a, 4b, 10a, and10b has been developed via ozonolysis of 2-endo-7-anti-diacylnorbornenes 3a, 3b,9a , and 9b. The synthesis of the unsubstituted (parent) compound 4a of tetraacetal tetraoxa-cages has been accomplished for the first time by this new entry. Ozonolysis reactions of 3a, 3b, and 9a were also performed in CDCl 3 for understanding the final ozonide structures and the ozonation chemistry. Ozonolysis of 3a, 3b, and 9a in CH 2 Cl 2 at -78 °C followed by treatment with triethylamine provided an indirect support for the structures of the final ozonides11a , 11b, and 14.