Syntheses of enantio-enriched chiral building blocks from L-glutamic acid

Abstract

Starting from lactone-amide 8, easily derived from L-glutamic acid, enantioselective syntheses of (S)-tetrahydrofuran 2-carboxamide derivative 2 and a protected (S)-3-hydroxypiperidin-2-one (3) are reported. The building block 3 was converted to (2S,3R)-3-hydroxypipecolamide (6) by a three-step procedure. A solvent altered H-bonding capacity leading to a highly chemoselective tosylation of the primary hydroxyl group in the presence of an alpha-hydroxy-carboxamide was observed. (c) 2006 Elsevier Ltd. All rights reserved.