.gamma.-Methyl-.gamma.-butyrolactone .gamma.-Pentalactone .gamma.-Valerolactone 108-29-2 2(3H)-Furanone, dihydr-5-methyl- 2(3H)-Furanone, dihydro-5-methyl- 4-Hydroxypentanoic acid lactone 4-Hydroxyvaleric acid lactone 4-Methyl-.gamma.-butyrolactone 4-Pentanolide 4-Valerolactone NSC33700 Pentanoic acid, 4-hydroxy-, .gamma.-lactone Valerolactone