Crystal structure of N'-[(1E)-1-(6-methyl-2,4-dioxo-3,4-di-hydro-2H-pyran-3-yl-idene)eth-yl]benzene-sulfono-hydrazide.

In the title compound, C14H14N2O5S, the mol-ecule exists in the enamine (C=C-NH) tautomeric form. The hydrazone fragment derived from the 3-acetyl-4-hy-droxy-6-methyl-2H-pyran-2-one moiety is approximately planar, with a maximum deviation of 0.1291 (11) Šfor the N atom bound to the S atom of the benzensulfono-hydrazide group. The latter adopts a gauche conformation relative to the hydrazone N-N bond, with an N-N-S angle of 113.54 (10)°. There is an intra-molecular N-H⋯O=C hydrogen bond that stabilizes the tautomeric form. In the crystal, mol-ecules are linked by N-H⋯O=C hydrogen bonds into chains extending parallel to [100].