(6R,7R)-7-((R)-2-amino-2-phenylacetamido)-3-methylene-8-oxo-5-thia-1-azabicyclo[4.2.0]octane-2-carboxylic acid; isocefalexine; (2R,6R,7R)- and (2S,6R,7R)-7-[[(2R)-2-amino-2-phenylacetyl]amino]-3-methylene-8-oxo-5-thia-1-azabicyclo[4.2.0]octane-2-carboxylic acid
