The N^im-(2,4-dimethylpent-3-yloxycarbonyl)(Doc) group, a new nucleophile-resistant, HF-cleavable protecting group for histidine in peptide synthesis

Abstract

The 2,4-dimethylpent-3-yloxycarbonyl group as protection for the imidazole ring of histidine combines several properties that makes it ideal for solid phase peptide synthesis with Boc chemistry; it is readily cleaved by liquid HF, stable to trifluoroacetic acid, soluble in apolar organic solvents and highly resistant to nucleophiles, thereby avoiding the danger of Nim to Nα transfer and premature cleavage by other nucleophiles during solid phase synthesis.