1-(4-hydroxybuta-1,2-dienyl)-5-methylpyrimidine-2,4-dione

1-(4-hydroxy-2-oxobutyl)-5-methylpyrimidine-2,4-dione

N1-(4-hydroxy-2-butyn-1-yl)thymine

N1-(4-acetoxy-2-butyn-1-yl)thymine

2-(2-hydroxyethyl)-6-methyl-7H-oxazolo[3,2-a]pyrimidin-7-one