SynopsisPreparations of four diol monomers containing nucleic acid bases and the corresponding model polymers of polynucleotides with linear polyester backbone and nucleic acid base derivative as pending side chains are described. N-(1',3'-Dihydroxy-2'-methyl-2'-propyl) -24thymin-I -yl)propionamide (Ia, HMPTPA), N~1',3dihydroxy-2-methyl-2-propyl)-2-uracil-l-y1)propionamide (Ib, HMPUPA), and their isomers, N-(P,fi'dihydroxyethyIb24thynin-l-y1)propionamide (IIa, HETPA) and N~,fi'dihydroxyethyl~24uracil-l-yl)propionamide (I&, HEUPA) were synthesized through the selective N-acylation of 2-methyl-2-aminc-1,3-propanediol and diethanolamine with 2-(thymin-l-yl)propionic acid CTPA) and 24uracil-l-y1)propionic acid (UPA), respectively, by the active amide-benzotriazole method. Diol monomers I and I1 were polycondenzed with active amide of benzotriazole such as l,l'-(isophthal-oyUbisbenzotriazole (IPBBT) in the presence of triethylamine and in DMF at W C , giving polyesters containing thymine and uracil derivatives as the side group. Prior to polymer synthesis, a n 0-acylation of Ia using the active monoamide 1-benzoylbenzotriazole was carried out as a model compound study.