Synthesis of Pyrrolidinyl PNA and Its Site-Specific Labeling at Internal Positions by Click Chemistry.

Pyrrolidinyl PNA with an α-/β-dipeptide backbone consisting of alternating nucleobase-modified D-proline and (1S,2S)-2-aminocyclopentanecarboxylic acid (also known as acpcPNA) is a class of conformationally constrained PNA that shows exceptional DNA hybridization properties including very high specificity and the inability to form self-pairing hybrids. In this chapter, details of the syntheses of acpcPNA as well as its monomers and a protocol for site-specific labeling with a fluorescent dye via click chemistry are reported.