1H-1,2,4-Triazole-1-ethanol, .alpha.-(2,4-difluorophenyl)-.alpha.-[(1R)-1-[[2-[(1E,3E)-4-phenyl-1,3-butadienyl]-1,3-dioxan-5-yl]phosphino]ethyl]-, (a1R)- AIDS-113633 AIDS113633