The photoelectron (PE) spectrum of cis-1,4,5,8-tetraoxadecalin exhibits in contrast to most polyoxa compounds an extremely well resolved low energy pan due to large 'through-bond' interactions between the oxygen lone pairs and the ideally oriented C-C bonds. The 'through-bond' interactions of the cis- as well as the unknown trans-1,4,5,8-tetraoxadecalin are discussed based on simple perturbation molecular orbital theory and PRDDO molecular orbital calculations. Additionally the PE spectrum of 2,2'-bis (1,3-dioxolane) is reported. Molecular mechanics (MM1 and MM2) and molecular orbital (PRDDO) calculations of the different conformations of the 1,4,5,8-telraoxadecalin and 2,2'-bis(1,3-dioxolane) systems allow the absence of the trans-1, 4,5,8-tetraoxadecalin, and the cis-trans energy difference in the series decalin, 1,8-dioxadecalin and 1,4,5,8-tetraoxadecalin systems to be explained.