4(R)-<1-buten-3(R)-yl>-3(S)-<1(R)-<(tert-butyldimethylsilyl)oxy>ethyl>-2-oxoazetidine

Sodium (1S,5R,6S)-2-Acetoxymethyl-6-<(R)-1-hydroxyethyl>-1-methylcarbapen-2-em-3-carboxylate

Sodium (1S,5R,6S)-2-(1-ethyl-1-H-tetrazol-5-yl)thiomethyl-6-<(R)-1-hydroxyethyl>-1-methylcarbapen-2-em-3-carboxylate

Sodium (1S,5R,6S)-6-<(R)-1-hydroxyethyl>-1-methyl-2-(3-sodiumcarboxy-2-pyridyl)thiomethylcarbapen-2-em-3-carboxylate

Sodium (1S,5R,6S)-6-<(R)-1-hydroxyethyl>-1-methyl-2-(4-oxo-4H-pyrido<1,2-a>pyrimidin-9-yl)thiomethylcarbapen-2-em-3-carboxylate