((2R,3S,4R,5R)-5-(4-aminopyrrolo(2,1-f)(1,2,4)triazin-7-yl)-5-cyano-3,4-dihydrox ytetrahydrofuran-2-yl)methyl isobutyrate
((2r,3s,4r,5r)-5-(4-aminopyrrolo(2,1-f)(1,2,4)triazin-7-yl)-5-cyano-3,4-dihydrox ytetrahydrofuran-2-yl)methyl isobutyrate