Synthesis of novel non-proteinogenic amino acids : n-ethyl-alpha, beta-dehydroamino acid methyl esters

• Main Author: Monteiro, Luís S.
• Publication Date: 2010
• Other Authors: Kołomańska, Joanna, Suárez, Ana C.
• Format: Article
• Language: eng
• Source: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Download full: http://hdl.handle.net/1822/17870
• topic: Nosylamino acids; α,β-dehydroamino acids; β-elimination; N-alkylation; Amino acids; alpha,beta-Dehydroamino acids; Alkylation; N-Ethyl-alpha,beta-dehydroamino acids; N-Ethyl-α-β-dehydroamino acids; Science & Technology

Two routes for the synthesis of N-ethyl-N-(4-nitrophenylsulfonyl)-alpha,beta-dehydroamino acid derivatives from serine, threonine and phenylserine derivatives are presented. One route consists of dehydration of N-(4-nitrophenylsulfonyl)-beta-hydroxyamino acid esters with di-tert-butyl dicarbonate catalyzed by 4-(dimethylamino)pyridine, followed by alkylation of the N-(4-nitrophenylsulfonyl)-alpha,beta-dehydroamino acid methyl esters obtained with triethyloxonium tetrafluoroborate. The second strategy applied the same procedures but in inverse order: alkylation followed by dehydration. These methods made it possible to obtain for the first time, new non-natural amino acids, which incorporate both an N-ethyl and an alpha,beta-dehydro moiety.