1(2H)-Pyrimidineacetamide, tetrahydro-N-[(1S,3S,4S)-3-hydroxy-5-phenyl-1-(phenylmethyl)-4-[[2-(2,4,6-trimethylphenoxy)acetyl]amino]pentyl]-.alpha.-(1-methylethyl)-2-oxo-, (a1S)- AIDS-121163 AIDS121163