The Chemistry of the Thiosulfinyl Group: Preparation, Structure, and Spectroscopic and Chemical Properties of Cyclic Thionosulfites

• Published in: Helvetica chimica acta 2005-06, Vol.88 (6), p.1451-1471
• Main Authors: Nakayama, Juzo, Yoshida (nee Tanaka), Sanae, Sugihara, Yoshiaki, Sakamoto, Akira
• Format: Article
• Language: English
• ISSN: 0018-019X; 1522-2675
• DOI: 10.1002/hlca.200590117

Treatment of the tetrahydrothiophene‐3,4‐diol 5 with 1,1′‐thiobis‐(1H‐benzimidazole) (6) furnished two diastereoisomers of the novel cyclic thionosulfite 4 with different configurations at the pseudo‐tetrahedral center of the thiosulfinyl (SS) group. The configuration of the SS group of the major diastereoisomer (isolated in 45% yield) was established to be syn to the thiolane ring, as determined by X‐ray crystallographic analysis, while that of the minor diastereoisomer (isolated in 10% yield) was anti. 1H‐NMR Spectroscopic analysis clarified that the shielding and deshielding zones of the SS group are similar to those of the well‐documented SO group. Characteristic absorptions of the SS group in the IR, Raman, and UV/VIS spectra were assigned on the basis of calculations at the B3LYP/6‐31G* level. The reactivity of the SS group toward thermolysis, hydrolysis, and oxidation was examined. The SS group is more resistant toward oxidation than the divalent sulfide S‐atom, but is oxidatively converted to the SO group.