Abstract

The synthesis of the thymine derivative (S)-50, was achieved in high enantiomeric purity (98% ee). The (R) enhanced enantiomer was also synthesized with moderate enantiomeric purity (46% ee). This acyclic pyrimidine analog ((S)-50) is a useful building block for the synthesis of a novel class of oligomers, the aromatic peptide nucleic acids (APNA). The APNA tetramer 70 was prepared from the amino acid monomer (S)-50 using classical peptide synthesis. Chemical shift differences between the $\sp1$H NMR of monomer (S)-57 and tetramer 70 were observed which suggested that base stacking interactions in the oligomers may be favorable.