(((2S,5R,6R)-3,3-dimethyl-7-oxo-6-((R)-2-((E)-(5-oxohexan-2-ylidene)amino)-2-phenylacetamido)-4-thia-1-azabicyclo[3.2.0]heptane-2-carbonyl)oxy)methyl 3,3-dimethyl-7-oxo-4-oxa-1-azabicyclo[3.2.0]heptane-2-carboxylate
(((2S,5R,6R)-3,3-dimethyl-7-oxo-6-((R)-2-((E)-(5-oxohexan-2-ylidene)amino)-2-phenylacetamido)-4-thia-1-azabicyclo[3.2.0]heptane-2-carbonyl)oxy)methyl 3,3-dimethyl-7-oxo-4-oxa-1-azabicyclo[3.2.0]heptane-2-carboxylate