Synthesis of difluorinated pseudopeptides using chiral α,α-difluoro-β-amino acids in the Ugi reaction
作者:Vanessa Gouge、Philippe Jubault、Jean-Charles Quirion
DOI:10.1016/j.tetlet.2003.11.019
日期:2004.1
2,2-Difluoro-3-(2-hydroxy-1 R-phenylethylamino)-3 S-phenylpropionic acid 3, obtained by a Reformatsky-type reaction of ethyl bromodifluoroacetate with (4R)-2,4-diphenyloxazolidine, was used as a classical carboxylic acid in the Ugi reaction to prepare various difluorinated pseudopeptides 5a-n. Compounds 5 were then deprotected by hydrogenolysis to furnish difluorinated pseudopeptides 6. (C) 2003 Elsevier Ltd. All rights reserved.