The geometries and energies of the conformers of oxocane, the isomeric di-and trioxocanes, and of 1,3,5,7-tetroxocane were calculated by molecular mechanics. A boat-chair conformation was preferred by all molecules. From the preference of oxygen in the boat-chair conformations of oxocane (position 3 over 1 over 4) the preferred boat-chair form of all other oxocanes can be derived. The results are compared to experi-mental data, which in part can be reinterpreted. Additional CNDO/2 and MINDO/3 calculations were performed for 1,3,5,7-tetroxocane.