886590-13-2

1-Azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid,3-[[1-(1-azetidinylthioxomethyl)-3-azetidinyl]thio]-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-, 1-[[(1-methylethoxy)carbonyl]oxy]ethyl ester,(4R,5S,6S)-