Thiazetidines and 1,2,3-Oxathiazetidines

Carbodi-imides undergo 1,2-cycloaddition to diphenylphosphinothioyl isothiocyanate and p-tolyl isothiocyanate across the C=S bond to give 1,3-thiazetidine derivatives,and not across the C=N bond as previously 

Aryl sulphinylamines reacted vidth aryl aldehydes to give crystalline 1 1 adducts formulated as 3,4-diaryloxathiazetidine 2-oxides, which decomposed on heating to give Schilf-bases and sulphur dioxide. Analogous adducts were formed with aliphatic aldehydes and ketones, but they were extremely unstable. 1,2,3-Oxathiazetidine intermediates have been postulated in other reactions. -  

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