AIDS-005459 AIDS005459 Penicillin Et(NH)2 dimer [2R-[2.alpha.(R*),4.beta.]2'R-[2'.beta.,4.alpha.]]-N-Ethyl-5,5-dimethyl-4-[[[2-[[[5,5-dimethyl-2-[[(phenylacetyl)amino]methyl]-4-thiazolidinyl]carbonyl]amino]ethyl]amino]carbonyl]-.alpha.-