An Improved Method for the Preparation of Protected (R)-2-Methylcysteine: Solution-Phase Synthesis of a Glutathione Analogue

Douglas S. Masterson, University of Southern Mississippi
Amanda Blair, University of Southern Mississippi


A synthetic method for the preparation of (R)-2-methylcysteine that dramatically improves the overall yield of this important unnatural amino acid has been refined. The key steps in the preparation of (R)-2-methylcysteine were improved such that necessary intermediates were prepared in high yields and of sufficient purity to avoid the need for distillation or column chromatography. The ( R)-2-methylcysteine was prepared (> 90% ee) in appropriately protected form and used in a novel solution phase synthesis of a glutathione analogue.