(6R,7R)-1-(((cyclohexyloxy)carbonyl)oxy)ethyl 7-(2-(2-aminothiazol-4-yl)acetamido)-3-(((1-(2-(dimethylamino)ethyl)-1H-tetrazol-5-yl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate