2(5H)-Furanone, 5-ethyl-, (5S)-

(3S,3aS,4R,4aS,8aS)-3-ethyl-4-hydroxy-3a,4,4a,5,6,7,8,8a-octahydronaphtho[2,3-c]furan-1(3H)-one

(3S,3aR,4S,9R,9aR)-4,9-epoxy-3-ethyl-3a,4,5,6,7,8,9,9a-octahydronaphtho[2,3-c]furan-1(3H)-one

(3S,3aR,4R,4aS,8aR,9S,9aR)-4,9-epoxy-3-ethyl-decahydronaphtho[2,3-c]furan-1(3H)-one

(3S,3aS,4R,4aS,8aR,9aS)-decahydro-4-hydroxy-3-ethylnaphtho[2,3-c]furan-1(3H)-one