Synonyms: 4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylicacid, 3,3-dimethyl-7-oxo-6-(2-phenylacetamido)-, hydroxymethyl ester acetate(ester) (8CI); 4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid,3,3-dimethyl-7-oxo-6-[(phenylacetyl)amino]- (2S,5R,6R)-, (acetyloxy)methylester (9CI); 4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid,3,3-dimethyl-7-oxo-6-[(phenylacetyl)amino]- [2S-(2a,5a,6b)]-, (acetyloxy)methyl ester;Penicillin G, hydroxymethyl ester, acetate (7CI); Methanediol, acetate3,3-dimethyl-7-oxo-6-(2-phenylacetamido)-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate(8CI); Acetoxymethyl benzylpenicillanate; Acetoxymethyl benzylpenicillinate;Benzylpenicillin acetoxymethyl ester; Havapen; Penamecillin; Penicillin Ghydromethyl ester acetate; Wy 20788