(3R,3aR,6aS)-3-(tert-butyldimethylsilanyloxymethyl)-3,3a,6,6a-tetrahydro-1H-cyclopenta[c]furan-1-one

(1aR,1bR,2R,4aS,5aS)-2-(tert-butyldimethylsilanyloxymethyl)hexahydro-4H-oxireno[3,4]cyclopenta[1,2-c]furan-4-one

(3R,3aR,6aS)-3-(hydroxymethyl)-3,3a,6,6a-tetrahydro-1H-cyclopenta[c]furan-1-one

(3R,3aS,6aR)-3-(hydroxymethyl)-6a-(phenylthio)-3,3a,6,6a-tetrahydro-1H-cyclopenta[c]furan-1-one

tert-butyl (3S)-3-[(2S)-1,4-dioxaspiro[4.5]dec-2-yl]pent-4-enoate