AIDS-005393 AIDS005393 C2-sym dimer Penicillin deriv. [2R-[2.alpha.(R*),4.beta.]]-4,4'-[1,2-Ethanediylbis[aminocarbonyl]]bis[N-ethyl-5,5-dimethyl-.alpha.-[(phenylacetyl)amino]-2-thiazolidineacetamide]