Boc-Lys(Boc)-Pro-OH is a protected amino acid derivative in which a lysine residue is doubly protected as an N-Boc and an additional Boc-protected side-chain amino group, and it is coupled to a proline carboxylic acid in a peptide-like arrangement. The molecule contains a free carboxylic acid at the proline terminus, while the lysine backbone amine and the lysine side-chain ε-amino group are masked as tert-butoxycarbonyl (Boc) carbamates, leaving the proline ring as a secondary amine-bearing cyclic residue with a conformationally restricted side chain. In synthesis, this protected Lys-Pro building block supports stepwise peptide assembly by providing orthogonal chemoselectivity through Boc deprotection and by maintaining the lysine nitrogens in a protected state to reduce undesired side reactions during coupling and subsequent derivatization.
CAT No: CP26614
CAS No:198475-99-9
Synonyms/Alias:Boc-Lys(Boc)-Pro-OH;198475-99-9;PubChem12319;SCHEMBL16924987;MolPort-020-004-611;C21H37N3O7;6407AH;ZINC15721570;AKOS025289355;AK170046;K-5807
Boc-Lys(Boc)-Pro-OH is a Boc-protected lysine derivative bearing an additional Boc-protected amino group on the lysine side chain, paired with a proline residue in the same protected amino acid building block. The molecule contains a Boc carbamate protecting group on the N-terminus and a second Boc group on the lysine side-chain amino functionality, while the proline ring provides a conformationally constrained cyclic backbone segment. This protected, diamino-functional amino acid unit is commonly used in peptide and peptidomimetic synthesis workflows where orthogonal side-chain handling and controlled reactivity are required.
1. Protected Peptide Building Block
Boc-Lys(Boc)-Pro-OH is used by peptide synthesis groups to assemble protected peptide segments that include lysine and proline in a defined sequence, particularly when both the lysine α-amino group and the lysine side-chain ε-amino group must remain masked during upstream coupling steps. The presence of two Boc-protected amino functions supports iterative fragment condensation strategies in which the lysine side chain is intentionally kept protected until a later deprotection and functionalization step. Custom peptide manufacturers and research labs frequently select this type of doubly protected lysine-proline building block to reduce side reactions associated with free diamines and to improve the reliability of subsequent peptide elongation and downstream derivatization.
2. Segment Condensation Intermediates
Boc-Lys(Boc)-Pro-OH is employed as a protected intermediate for preparing peptide segments used in solution-phase or solid-phase workflows, where a lysine-containing motif must be introduced without premature side-chain reactivity. In medicinal chemistry and peptidomimetic development, this building block helps enable the construction of longer sequences by providing a controlled, protected lysine unit that can be carried through multiple coupling cycles. The proline residue contributes conformational constraint that is often leveraged in sequence design to probe structure-property relationships, while the dual Boc protection pattern supports staged deprotection/functionalization strategies during final assembly.
3. Lysine Side-Chain Staged Functionalization
Boc-Lys(Boc)-Pro-OH supports workflows that require lysine ε-amino group handling at a specific stage, such as preparing peptides for later conjugation, branching, or incorporation of additional protected substituents. Because both amino sites are Boc-protected in the supplied building block, researchers can maintain tight control over which nitrogen is unmasked during the synthetic timeline, improving compatibility with protecting-group orthogonality plans used in complex peptide synthesis. This makes the reagent useful for teams building multi-step peptide constructs where lysine side-chain modification is deferred to a controlled point after the backbone has been assembled and purified.
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