.alpha.-Butyrolactone .gamma.-6480 .gamma.-BL .gamma.-Butyrolactone .gamma.-Hydroxybutyric acid cyclic ester .gamma.-Hydroxybutyric acid lactone .gamma.-Hydroxybutyrolactone 1,2-Butanolide 1,4-Butanolide 2(3H)-Furanone, dihydro- 4-Butanolide 4-Butyrolactone 4-Deoxytetronic acid 4-Hydroxybutanoic acid lactone 4-Hydroxybutanoic acid, .gamma.-lactone 4-Hydroxybutyric acid lactone 4-Hydroxybutyric acid, .gamma.-lactone 96-48-0 BLO BLON Butanoic acid, 4-hydroxy-, .gamma.-lactone Butyric acid lactone Butyric acid, 4-hydroxy-, .gamma.-lactone Butyrolactone Butyryl lactone Butyrylactone Dihydro-2(3H)-furanone Dihydro-2-furanone NCI-C55878 NSC4592 Tetrahydro-2-furanone WLN: T5OVTJ