6533b7dbfe1ef96bd126fe73

RESEARCH PRODUCT

Synthesis of peptides with α,β-dehydroamino acids, VI. Synthesis ofN-benzyloxycarbonyl andN-trifluoroacetyl dipeptides of α,β-dehydro-butyrine, -valine, -leucine, and -isoleucine

subject

description

Condensation of Z- and TFA-amino acid amides with 2-oxo-acids, namely butanoic, 3-methylbutanoic, 4-methylpentanoic, and (3RS)-3-methylpentanoic acid, yields (in the presence of p-toluenesulfonic acid as a catalyst) Z- and TFA-dipeptides with C-terminal ΔAbu2) (1–4), ΔVal (5–8), ΔLeu (9–11), and ΔIle (12–15) (Table 1).