((1S,2S)-1-{N'-[1-((2R,5S)-5-Hydroxymethyl-tetrahydro-furan-2-yl)-2-oxo-1,2-dihydro-pyrimidin-4-yl]-hydrazinocarbonyl}-2-methyl-butyl)-carbamic acid tert-butyl ester AIDS-211850 AIDS211850 C-4-(N-Butyloxycarbonyl-isoleucine hydrazide)-ddC