STEREOSELECTIVE SYNTHESIS OF CIS AND TRANS N-TOSYL SULPHILIMINES AND SULPHOXIDES FROM 2-ALKYLTHIANES AND 2-ALKYLTHIOLANES ASSIGNMENTS OF CONFIGURATIONS AND PREFERRED CONFORMATIONS

Article abstract of DOI:10.1016/S0040-4020(01)88170-9

Thiane and thiolane derivatives with 2-methyl, 2-ethyl, 2-isopropyl and 2-tert-butyl groups were prepared and converted to cis and trans sulphilimines and sulphoxides by various stereoselective methods.Cis-sulphilimines were formed by using t-BuOCl and TsNH^- in a two-stage process, while cyclic sulphides were converted by chloramine-T predominantly to trans-sulphilimines.Sulphoxides enriched in cis and trans isomers were obtained by different methodes of oxidation.Diastereoisomeric product distributions were measured by hplc and the configurations of diastereoisomers were assigned by 13C NMR spectroscopy.Preferred conformations of sulphilimines were determined by analysis of 13C NMR and X-ray data.As shown by 13C NMR spectra, the conformations of sulphilimines and sulphoxides are analogous.