(S)-5-((S)-2,2-Dimethyl-[1,3]dioxolan-4-yl)-3-((E)-3-hydroxy-propenyl)-5H-furan-2-one

(S)-5-((S)-1,2-Dihydroxy-ethyl)-3-((E)-3-hydroxy-propenyl)-5H-furan-2-one

(S)-5-((S)-1,2-Dihydroxy-ethyl)-3-((1E,3E)-5-hydroxy-penta-1,3-dienyl)-5H-furan-2-one

5-[2-(tert-Butyl-dimethyl-silanyloxy)-eth-(Z)-ylidene]-3-[(E)-3-(tert-butyl-dimethyl-silanyloxy)-propenyl]-5H-furan-2-one

(S)-5-[(S)-2-(tert-Butyl-dimethyl-silanyloxy)-1-hydroxy-ethyl]-3-[(E)-3-(tert-butyl-dimethyl-silanyloxy)-propenyl]-5H-furan-2-one