Asymmetric alpha-alkylation of alpha-amino esters using pyridoxal derivatives having a chiral ansa-structure and a chiral ionophore function: a novelexample of double asymmetric induction

Stereoselective alkylation of aldimines, prepared from cr-amino esters and a pyridoxal model having a chiral ansa-structure and an ethoxyethoxy group at C-3, proceeded in the presence of Li+ to give alpha,alpha-dialkyl amino esters after acidic hydrolysis. Double asymmetric induction effect was also observed in the alkylation reaction by combination of the chiral ansa-stru cture and a chiral ionophore side chain at C-3. (C) 2000 Elsevier Science L td. All rights reserved.