Two New Protecting Groups for the Guanidino Function of Arginine

Article abstract of DOI:10.1002/prac.19953370103

Two new synthons, Fmoc-L-Arg(biphenyl-4-sulphonyl)-OH (8) and Fmoc-Arg(4-methoxy-3-t-butylbenzenesulphonyl)-OH (14), are prepared for the synthesis of arginine-containing peptides.These groups are cleaved by commonly employed trifluoroacetic acid and methanesulphonic acid.Kinetic studies reveal that extended bicyclic aromatic conjugation, as in biphenyl, slightly improves the acid lability compared to the electron-donating t-butyl group.