The reactions of oxaziridines 1 with carbon disulfide (2) and phenyl isothiocyanate (8) have been studied. With carbon disulfide, 2-n-alkyl-or see-alkyloxaziridines give alkyl isothiocyanates (quantitatively), carbonyl compounds, and sulfur. Similar reactions between 1 and 8 form carbodiimides 9, but under mild experimental conditions 1 and 8 react to yield considerable amounts of either and/or the thiadiazolidinethione isomers 10 and 11. 2-tert- ...