2-Thiazolidineacetamide, 4-[[[2-[[[5,5-dimethyl-2-[2-oxo-1-[(phenylacetyl)amino]-2-[(phenylmethyl)amino]ethyl]-4-thiazolidinyl]carbonyl]amino]ethyl]amino]carbonyl]-5,5-dimethyl-.alpha.-[(phenylacetyl)amino]-N-[4-(tert-butoxycarbonyl)phenyl]methyl)-,[2R-[2.alpha.(R*),4.beta.[2R*(R*),4S*]]]- AIDS-029862 AIDS029862 Penicillin G, ET(NH)2 deriv.