2H-Pyran-2-one, 5,6-dihydro-6-pentyl- 5,6-Dihydro-6-pentyl-2H-pyran-2-one 5-Hydroxy-2-decenoic acid, delta-lactone 5-Hydroxy-2-decenoic acid, delta-lactone (natural) 54814-64-1 EINECS 259-359-9 FEMA No. 3744