AIDS-005371 AIDS005371 Penicillin Et(NH)2 dimer [2R-[2.alpha.(R*),4.beta.]]-4,4'-[1,2-Ethanediylbis[aminocarbonyl]]bis[N,N-pentamethylene-5,5-dimethyl-.alpha.-[(phenylacetyl)amino]-2-thiazolidineacetamide]