Acetic acid (3aR,3bS,6S,6aS,7aR)-2,2-dimethyl-5-oxo-hexahydro-furo[2',3':3,4]cyclopenta[1,2-d][1,3]dioxol-6-yl ester

Acetic acid (R)-5-((4S,5S)-5-bromomethyl-2,2-dimethyl-[1,3]dioxolan-4-yl)-2-oxo-2,5-dihydro-furan-3-yl ester

Acetic acid (2S,3S,4R)-4-acetoxy-2-((4S,5S)-5-bromomethyl-2,2-dimethyl-[1,3]dioxolan-4-yl)-5-oxo-tetrahydro-furan-3-yl ester