.alpha.-Methyl-.gamma.-butyrolactone .alpha.-Methylbutyrolactone 1679-47-6 2(3H)-Furanone, dihydro-3-methyl- 2-Methyl-.gamma.-butyrolactone 2-Methyl-4-butanolide 2-Methylbutanolide 4-Hydroxy-2-methylbutanoic acid lactone 4-Hydroxy-2-methylbutyric acid lactone NSC102837