(S)-5-[(R)-((4S,5R)-2,2,5-Trimethyl-[1,3]dioxolan-4-yl)-trimethylsilanyloxy-methyl]-5H-furan-2-one

(4R,5S)-5-[(R)-(tert-Butyl-dimethyl-silanyloxy)-((4S,5R)-2,2,5-trimethyl-[1,3]dioxolan-4-yl)-methyl]-4-vinyl-dihydro-furan-2-one

(S)-5-[(R)-(4-Methoxy-benzyloxy)-((4S,5R)-2,2,5-trimethyl-[1,3]dioxolan-4-yl)-methyl]-5H-furan-2-one

{(2S,3R)-5-Hydroxy-2-[(R)-(4-methoxy-benzyloxy)-((4S,5R)-2,2,5-trimethyl-[1,3]dioxolan-4-yl)-methyl]-tetrahydro-furan-3-yl}-acetic acid tert-butyl ester