2-Pentenoic acid, 4-[[(2S)-2-[3-[[(5-methyl-3-isoxazolyl)carbonyl]amino]-2-oxo-1(2H)-pyridinyl]-1-oxo-4-pentynyl]amino]-5-[(3S)-2-oxo-3-pyrrolidinyl]-, 1,1-dimethylethyl ester, (2E,4S)- AIDS-185175 AIDS185175