Synonyms: 4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylicacid, 6-amino-3,3-dimethyl-7-oxo-, hydroxymethyl ester pivalate (ester),monohydrochloride (8CI); Methanediol,6-amino-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylatepivalate (ester) monohydrochloride (8CI); Pivalic acid, ester withhydroxymethyl 6-amino-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate,monohydrochloride (8CI); Pivalic acid, hydroxymethyl ester6-amino-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylatemonohydrochloride (8CI); Pivaloyloxymethyl 6-aminopenicillanate hydrochloride