First stereoselective synthesis of an optically pure β-substituted histidine: (2S,3S)-β-methylhistidine

We report the first example of the asymmetric synthesis of the β-substituted histidine, (2S,3S)-β-methylhistidine. A key in the synthesis is the use of the protecting group, 2-mesitylenesulfonyl (Mts-), for the imidazole ring to minimize epimerization during synthesis.