4-Thia-1-azabicyclo(3.2.0)heptane-2-carboxylic acid, 6-((carboxy-3-thienylacetyl)amino)-3,3-dimethyl-7-oxo-, (2S-(2alpha,5alpha,6beta(S*)))-
(2S,5R,6R)-6-{[(2R)-2-carboxy-2-thiophen-3-ylacetyl]amino}-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid