Shielding effect of thioether C–S bond from proton chemical shifts of 4-thia-5α- and 4-thia-5β-androstane-17-ones

4-Thia-5α- and 4-thia-5β-androstan-17-ones ( and ) were synthesized in order to obtain the NMR shielding parameters for the thioether C–S bond. The complete NMR assignment of both the proton and carbon atoms for these compounds and substituent-induced shifts (SIS) from the corresponding androstanones ( and ) are presented. A combination of the electric field effect and the anisotropy of the magnetic susceptibility of the C–S bond can successfully reproduced the observed SIS values for these androstanones.