4-Thia-1-azabicyclo(3.2.0)heptane-2-carboxylic acid, 3,3-dimethyl-7-oxo-6-((phenylacetyl)amino)-(2S-(2alpha,5alpha,6beta))-, (acetyloxy)methyl ester 983-85-7 EINECS 213-571-8 Hydroxymethyl (2S,5R,6R)-3,3-dimethyl-7-oxo-6-(2-phenylacetamido)-4-thia-1-azabicyclo(3.2.0)heptane-2-carboxylate, acetate (ester) PENAMECILLIN Penamecilina [INN-Spanish] Penamecillin [USAN:BAN:INN] Penamecillina [DCIT] Penamecilline [INN-French] Penamecillinum [INN-Latin] WY 20,788