2-ETHYLBUTANOYLOXYMETHYL (5R,6S)-6-((1R)-1-HYDROXYETHYL)-7-OXO-3-((1S,3S)-1-OXOTHIOLAN-3-YL)SULFANYL-4-THIA-1-AZABICYCLO(3.2.0)HEPT-2-ENE-2-CARBOXYLATE
2-ethylbutanoyloxymethyl (5r,6s)-6-((1r)-1-hydroxyethyl)-7-oxo-3-((1s,3s)-1-oxothiolan-3-yl)sulfanyl-4-thia-1-azabicyclo(3.2.0)hept-2-ene-2-carboxylate