(2'R,3R,4R,4aS,7aR)-methyl-3-hydroxy-4'-((S)-1-hydroxyethyl)-5'-oxo-3,4,4a,7a-tetrahydro-1H,5'H-spiro(cyclopenta(c)pyran-7,2'-furan)-4-carboxylate
(2'r,3r,4r,4as,7ar)-methyl-3-hydroxy-4'-((s)-1-hydroxyethyl)-5'-oxo-3,4,4a,7a-tetrahydro-1h,5'h-spiro(cyclopenta(c)pyran-7,2'-furan)-4-carboxylate