Bishydroperoxide (III) was prepared by treatment of cyclododecanone (I) with hydrogen peroxide in formic acid or, alternatively, by ozonolysis of vinyl ether (II) in the presence of hydrogen peroxide at -70 C. Alkylation of bishydroperoxide (III) with 1,3-diiodopropane (IV) and CsOH in DMF furnished the title spirotetraoxane.