Synthesis and reactivity of 1,2,4‐oxathiazolidin‐3‐imines

Abstract

Thiatriazoline 4a decomposes in acetone and yields a thermolabile crystalline material, identified as the 1,2,4‐oxathiazole derivative 6a on the basis of ir, 1H and 13C nmr spectroscopy. It degrades to 7a in the crystalline state as well as in solution. Cycloaddition‐elimination reactions of 6a with isothiocyanates proceed rapidly and furnish the same products as previously obtained from 4a. Some other reactions of 4 with carbonyl compounds were briefly investigated and provide evidence for the formation of unstable 1,2,4‐oxathiazolidines.