Synthesis of Dehydrodipeptide and N-ethyl-dehydrodipeptide Derivatives with an α-Aminoisobutyric Acid Residue

Title:Synthesis of Dehydrodipeptide and N-ethyl-dehydrodipeptide Derivatives with an α-Aminoisobutyric Acid Residue

Volume: 8 Issue: 2

Author(s): LuIs S. Monteiro, Silvia M.M.A. Pereira-Lima and Sofia Pereira

Affiliation:

Keywords: Alkylation, dehydration, dehydroamino acids, dehydrodipeptides, α, α-Dialkylglicines, N-Alkyl-dehydrodipeptides, N-Alkylamino acids.

Abstract: Several dipeptides with an N-benzyloxycarbonyl or an N-(tert-butyloxycarbonyl) α-aminoisobutyric acid residue and a β-hydroxyamino acid methyl ester were subjected to dehydration to form dehydrodipeptide derivatives. N-Ethylation of these dipeptides using triethyloxonium tetrafluoroborate with potassium tert-butoxide as auxiliary base led to complex mixtures that failed to render pure products. However, when the 4-nitrophenylsulfonyl protecting group was substituted for the benzyloxycarbonyl or tert-butyloxycarbonyl groups and N,N-diisopropylethylamine was substituted for potassium tert-butoxide, the dehydrodipeptide derivatives were selectively N-alkylated at the amino terminal nitrogen in fair to high yields. Alternatively, N-ethylation can be carried out prior to dehydration. Thus, through a combination of dehydration and N-ethylation procedures, it was possible to obtain dipeptides with α-aminoisobutyric acid and dehydroamino acid residues, which are N-alkylated at the amino terminal nitrogen.

Cite this article as:

Monteiro S. LuIs, Pereira-Lima Silvia M.M.A. and Pereira Sofia, Synthesis of Dehydrodipeptide and N-ethyl-dehydrodipeptide Derivatives with an α-Aminoisobutyric Acid Residue, Current Chemical Biology 2014; 8 (2) . https://dx.doi.org/10.2174/2212796809999150204114112