Amino acids and peptides. Part 45. Development of a new N<sup>π</sup>-protecting group of histidine, N<sup>π</sup>-(1-adamantyloxymethyl)histidine, and its evaluation for peptide synthesis
N π -(1-Adamantyloxymethyl)histidine, His(Nπ-1-Adom), is prepared and its properties are examined. The 1-Adom group can be easily removed by trifluoroacetic acid and it is stable to 20% piperidine–dimethylformamide and 1 mol dm–3 NaOH. His(Nπ-1-Adom) derivatives can suppress racemization during coupling reactions. His(Nπ-1-Adom) can be used in solid-phase peptidesynthesis in combination with fluor