β-Amino esters derived from the stereoselective conjugate addition of homochiral lithium N-benzyl-N-α-methyl-4-methoxybenzylamide to α,β-unsaturated esters may be orthogonally mono-N-deprotected under either oxidative or acid-promoted reaction conditions. Further oxidative deprotection affords β-amino acids or β-lactams. © 2001 The Royal Society of Chemistry.
