Fungicidal 3-(N-acyl-N-arylamino)-gamma-butyrolactones and gamma-butyrothiolactones

A compound of the formula ##STR14## wherein Ar is phenyl, naphthyl, or phenyl or naphthyl substituted with 1 to 4 of the same or different substituents selected from fluoro, chloro, bromo, alkyl of 1 to 4 carbon atoms or alkoxy of 1 to 4 carbon atoms;

• R.sup.1 is hydroxymethyl, halomethyl of 1 to 3 of the same or different halogens selected from fluoro, chloro, bromo, cycloalkyl of 3 to 6 carbon atoms, cycloalkyl of 3 to 6 carbon atoms substituted with 1 to 4 of the same or different substituents selected from alkyl of 1 to 4 carbon atoms, fluoro, chloro, bromo, hydroxy or alkoxy of 1 to 4 carbon atoms;
• and R.sup.2 is hydrogen, chloro, bromo, alkyl of 1 to 6 carbon atoms, phenyl or phenyl substituted with 1 to 2 of the same or different substituents selected from fluoro, chloro, bromo and alkyl of 1 to 6 carbon atoms;
• and Y is O, with the proviso that when Ar is phenyl or substituted phenyl R.sup.1 is not halomethyl, and with the further proviso that R.sup.1 is not cyclopropyl.