1-乙基-4-羟基-6-甲基吡啶-2(1H)-酮 、
3',5'-di-O-acetyl-2'-deoxy-5-formyluridine 、
丙二腈 反应 3.0h,
以82%的产率得到2-amino-4-[1-(3,5-di-O-acetyl-2-deoxy-β-D-ribosyl)-1,2,3,4-tetrahydropyrimidin-5-yl]-5,6-dihydro-6-ethyl-7-methyl-5-oxo-4H-pyrano[3,2-c]pyridine-3-carbonitrile