Asymmetric synthesis, that is, diastereoselective alkylation of a chiral auxiliary, is an important tool in organic
synthesis. In this work, an α-methyl, non-natural amino acid (NNAA) building block equipped with a phthalimide
group tail was prepared. This work describes the generation of the lithium enolate for an oxazolidin-2-one chiral
auxiliary derived from a NNAA followed by quenching this enolate with 2-chloromethyl-isoindole-1,3-dione to
provide an α-methyl NNAA building block equipped with a phthalimide group in good yield through a multistep
synthesis with no signs of any minor diastereomers. The identity of this compound was confirmed by 1H NMR
(Proton Nuclear Magnetic Resonance) and 13C NMR (Carbon-13 Nuclear Magnetic Resonance) spectroscopy.
With the availability of this building block, peptides can be produced and evaluated over a variety of therapeutic
areas in drug discovery.
