.gamma.,.gamma.-Dimethyl-.gamma.-butyrolactone .gamma.,.gamma.-Dimethylbutyrolactone .gamma.-Isocaprolactone .gamma.-Methyl-.gamma.-valerolactone 2(3H)-Furanone, dihydro-5,5-dimethyl- 3123-97-5 4-Methyl-4-hydroxypentanoic acid lactone 4-Methyl-4-pentanolide 4-Methylpentan-4-olide Dihydro-5,5-dimethyl-2(3H)-furanone Dimethylbutyrolactone Isocaprolactone NSC221122 Tetrahydro-5,5-dimethyl-2-furanone