Thioacetic acid S-((3R,6S,7aS)-3-methyl-1-oxo-3-propyl-hexahydro-pyrrolo[1,2-c]imidazol-6-yl) ester

(4R,5S,6S)-6-((R)-1-Hydroxy-ethyl)-4-methyl-3-((3R,6S,7aS)-3-methyl-1-oxo-3-propyl-hexahydro-pyrrolo[1,2-c]imidazol-6-ylsulfanyl)-7-oxo-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid