The function of protecting groups is to isolate specific functional groups during the synthesis process, protecting them from interference, and only removing the protecting groups after completing specific reactions to restore the activity of the target molecule. The process of removing protective groups usually requires mild conditions to avoid damaging the target molecule. For example, the method of removing ROH from protected alcohols is usually to produce ethers (ROR ') or esters (ROCOR'), and then hydrolyze or acidify them under appropriate conditions.
In summary, the role of protecting groups in PNA synthesis is crucial, as it ensures efficient synthesis of complex molecules, avoids non target reactions, and can be selectively removed when necessary to obtain purified PNA products.