(pivaloyloxy)methyl (2R,6R,7R)-7-((Z)-2-(2-aminothiazol-4-yl)-2-(methoxyimino)acetamido)-3-(((1-methyl-1H-tetrazol-5-yl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-3-ene-2-carboxylate

(6R)-7t-[2-(2-amino-thiazol-4-yl)-2-(Z)-methoxyimino-acetylamino]-3-(1-methyl-1H-tetrazol-5-ylsulfanylmethyl)-8-oxo-(6rH)-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid 2,2-dimethyl-propionyloxymethyl ester