A versatile method for the synthesis of (S)- or (R)-cycloalkylglycines, (S)- or (R)-N-Heterocyclic and α,β-unsaturated N-heterocyclic α-amino acids

Abstract Two different types of cyclic α-amino acids, cycloalkylglycines and N-heterocyclic α-amino acids, were prepared in optically pure form from the same chiral synthon 1- ( R ) (or 1- ( S )) simply by altering the quantity or type of base required for anion formation. Elaboration of the heterocyclic intermediate 3 provided α,β-unsaturated N-heterocyclic α-amino acids.