2,4-Dimethyl-.alpha.-pyrone 2H-Pyran-2-one, 4,6-dimethyl- 4,6-Dimethyl-.alpha.-pyrone 4,6-Dimethyl-2-pyrone 4,6-Dimethylcoumalin 675-09-2 Mesitene lactone NSC402790 WLN: T6OVJ D1 F1