[en] Following a general introduction the theory and analysis of NMR spectra are discussed, with special reference to the structural determination in the work to be presented, including computer analysis. The interpretation of spectral parameters, proton chemical shifts, C-13 chemical shift, lanthanide induced chemical shifts and ASIS are discussed and the experimental results presented in tabular form. Proton-proton and vicinal coupling constants are discussed for trimethylene sulphites and five-membered sulphites and C 13-H coupling constants for trimethylene sulphites. Finally the conformations of trimethylene sulphites, and ethylene sulphites and analogous five membered ring systems are discussed. In an appendix the experimental procedures are briefly presented, and also the computer programmes available for analysis of NMR spectra. A subroutine CONNOR is briefly presented which is substituted for subroutines in an original programme. Nine previously published papers by the author are also in-cluded in the appendix. (JIW)