Résumé : It has been possible to assign by infrared spectroscopy relative conformation to a number of stereomeric 1,2‐alkanediols. Spectra of the cyclic sulfites obtained from these diols are given, and it is shown that on subsequent acid hydrolysis the recovered diols entirely retain their initial configuration. Copyright © 1961 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim