Differentiation between 1,2,4,5-tetraoxanes and 1,2,4,5,7,8-hexaoxonanes using 1H and 13C NMR analyses

The proton and carbon resonance spectra of ten pairs of 1,2,4,5-tetraoxanes and 1,2,4,5,7,8-hexaoxonanes derived from acyclic and cyclic ketones have been recorded. A reliable method for distinguishing between 1,2,4,5-tetraoxanes and 1,2,4,5,7,8-hexaoxonanes by inspection of their chemical shifts, signal number, signal shape, and dynamic features has been developed. This method provides a rapid structural assignment of 1,2,4,5-tetraoxanes and 1,2,4,5,7,8-hexaoxonanes without using vapor pressure osmometry, isotope labeling or low temperature NMR techniques.