Intramolecular ester enolate-imine cyclization reactions for the asymmetric synthesis of polycyclic beta-lactams and cyclic beta-amino acid derivatives

Enolates of chiral N-(alpha-methyl-p-methoxybenzyl)-omega-imino-esters undergo intramolecular cyclization reactions to afford (syn)-aza-anions of beta-amino esters in high dr that cyclize to afford N-(alpha-methyl-p-methoxybenzyl)-beta-lactams that can be readily deprotected to afford their corresponding cyclic NH-beta-lactams, beta-amino esters, or beta-amino acids.