. Adamantyl-1,3,4-oxathiazol-2-one has been prepared for the first time and from it 1-adamantyl nitrile sulphide has been generated. Characterisation data are presented, including the X-Ray crystal structure of the oxathiazolone. (Crystal data for C,,H,,NO,S: monoclinic, space group F'2,/c, a = 11.334(2) A, b = 7.344(1) A, c = 14.373(2) A, P = 107.74(1)", V = 1139.5(3) AS, Z = 4, R = 0.042). The planar heterocyclic ring is similar to structures observed in the gas phase for other oxathiazolone derivatives. The nitrile sulphide was reacted with dimethyl-acetylene dicarboxylate in situ to give an isothiazole derivative. On a prtparC l'adamantyl-l,3,4-oxathiazol-2-one pour la premikre fois et on l'a utilise pour gCnCrer la sulfure de l-adamantyl nitrile. On prCsente les donntes ayant semi ?i sa caractCrisation, y compris la structure de l'oxathiazolone determinee par diffraction des rayons X. Les donntes cristallines pour C,,H,,NO,S sont les suivantes: cristaux monocliniques, groupe d'espace [Traduit par la Rtdaction]