Abstract:
Attempted preparation of the immunoadjuvant lipopeptide Pam2CysSKKKKG by Boc SPPS resulted in unexpected cleavage of the palmitoyl esters during HF-mediated cleavage from the resin. An alternative strategy using a combination of a sulfonamide linker, Fmoc SPPS and milder deprotection conditions afford the requisite peptide with the palmitoyl groups intact.