Asymmetric α-Alkylation of α-Amino Esters Using Pyridoxal Derivatives Having a Chiral Ansa-Structure and a Chiral Ionophore Function: a Novel Example of Double Asymmetric Induction

Stereoselective alkylation of aldimines, prepared from α-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 α,α-dialkyl amino esters after acidic hydrolysis. Double asymmetric induction effect was also observed in the alkylation reaction by combination of the chiral ansa-structure and a chiral ionophore side chain at C-3.