Stereoselective synthesis of novel conformationally restricted β- and γ-amino acids

Novel conformationally restricted β- and γ-amino acids containing a cyclopropane ring could be stereoselectively synthesized from readily available 5-methoxyindole and pyridine by copper(I)-catalyzed cyclopropanation with methyl diazoacetate followed by subsequent oxidative cleavage of the resulting adducts.