2,2-dimethylpropanoyloxymethyl (6R,7R)-7-amino-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate hydrochloride, 5-Thia-1-azabicyclo(4.2.0)oct-2-ene-2-carboxylic acid,7-amino-3-methyl-8-oxo-,(2,2-dimethyl-1-oxopropoxy)methyl ester,monohydrochloride,(6R-trans), (Pivaloyloxy)methyl (6R-trans)-7-amino-3-methyl-8-oxo-5-thia-1-azabicyclo(4.2.0)oct-2-ene-2-carboxylate monohydrochloride, EINECS 260-608-9,