(3S)-3-(N-{(1S)-1-[N-((1S)-1-{[(5S,1R)-8-Ethyl-6-(methylsulfonyl)-7-oxo-2,6-diazabicyclo[3.3.0]oct-2-yl]oxycarbonyl}-2-methylpropyl)carbamoyl]-2-methylpropyl}carbamoyl)-3-(acetylamino)propanoic acid AIDS-154667 AIDS154667