ChemInform Abstract: Asymmetric Chelated Claisen Rearrangements in the Presence of Chiral Ligands — Scope and Limitations.

Abstract

diastereoselective syntheses, enantioselective syntheses diastereoselective syntheses, enantioselective syntheses (incl. cis/trans-isomerism) O 0031 -034Asymmetric Chelated Claisen Rearrangements in the Presence of Chiral Ligands -Scope and Limitations.-A variety of chiral amino alcohols and metal salts is investigated in the asymmetric Claisen rearrangement of appropriate glycine esters. Best results are obtained using cinchona alkaloids and Al(O-iPr) 3 . Enantiomeric products can be obtained either by changing the chiral ligand or by changing the reactions conditions using the same ligand (generation of Al-vs. Li-enolates). Ligand acceleration is not observed. -