Synthesis of chiral peptide nucleic acids using Fmoc chemistry

A Fmoc-based synthesis of chiral PNAs is described. Chiral monomer backbones were efficiently prepared by reductive amination of N-Fmoc-protected l,d-alaninals with glycine esters and the subsequent acylation of free amines with thymine-1-ylacetic acid. The dimer derivative of l-amino acid was prepared in solution. Finally, a chiral decamer was obtained by a solid phase strategy using a succinyl-linked support.