Please use this identifier to cite or link to this item:

TitleSynthesis of substituted oxazoles from N-acyl-beta-hydroxyamino acid derivatives
Author(s)Ferreira, Paula M. T.
Monteiro, Luís S.
Pereira, Goreti
KeywordsAmino acids
Dehydroamino acids
Oxygen heterocycles
Nitrogen heterocyles
Issue dateSep-2008
PublisherWiley-VCH Verlag
JournalEuropean Journal of Organic Chemistry
Abstract(s)Several N-acyl-beta-hydroxyamino acids were prepared and treated with di-tert-butyl dicarbonate in the presence of 4-(dimethylamino)pyridine, followed by treatment with N,N,N',N'-tetramethylguanidine to give the corresponding N-acyldehydroamino acids in good to high yields. These were then treated with I-2/K2CO3 followed by 1,8-diazabicyclo[5.4.0]undec-7-ene. The methyl esters of N-acyldehydroaminobutyric acid gave the corresponding substituted oxazoles in good to high yields. The N-acyldehydrophenylalanines gave 5-phenyloxazole derivatives in low to moderate yields together with beta-iododehydrophenylalanines. Under the same conditions, N-acyldehydroalanines failed to give the corresponding oxazoles. However, when the reaction was carried out in the absence of DBU, it was possible to isolate the beta,beta-diiododehydroalanine derivatives. Although the reason for the different reactivities of the N-acyldehydroamino acids is not completely clear to us, cyclic voltammetry studies showed that the less-reactive derivatives have higher reduction potentials. This suggests that the double bonds in dehydroaminobutyric acid derivatives are more susceptible to electrophilic attack by iodine. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).
Publisher version
AccessOpen access
Appears in Collections:CDQuim - Artigos (Papers)

Files in This Item:
File Description SizeFormat 
2008-Eur. J. Org. Chem. 4676.pdf208,17 kBAdobe PDFView/Open

Partilhe no FacebookPartilhe no TwitterPartilhe no DeliciousPartilhe no LinkedInPartilhe no DiggAdicionar ao Google BookmarksPartilhe no MySpacePartilhe no Orkut
Exporte no formato BibTex mendeley Exporte no formato Endnote Adicione ao seu ORCID