(-)-7α-hydroxy-6β-triphenylmethoxymethyl-cis-2-oxabicyclo[3.3.0]octan-3-one

(3aR,4S,5R,6aS)-5-(tert-butyldiphenylsilyloxy)-4-(trityloxymethyl)hexahydro-2H-cyclopenta [b] furan-2-one

(3aR,4R,5R,6aS)-5-(tert-butyldiphenylsilyloxy)-4-((E)-3-oxo-5-phenylpent-1-enyl)hexahydro-2H-cyclopenta[b]furan-2-one

(3aR,4R,5R,6aS)-5-(tert-butyldiphenylsilyloxy)-4-((S,E)-3-hydroxy-5-phenylpent-1-enyl)hexahydro-2H-cyclopenta[b]furan-2-one