Convenient, asymmetric synthesis of enantiomerically pure 2',6'- dimethyltyrosine (DMT) via alkylation of chiral equivalent of nucleophilic glycine

Asymmetric synthesis of (S)-2',6'-dimethyltyrosine (DMT) via reactions of 4'-benzyloxy-2',6'-dimethylbenzyl bromide with Ni(II)-complexes of the chiral Schiff base of glycine with (S)-o-[N-(N-benzylprolyl)amino]- benzophenone was developed. Inexpensive and readily available reagents and solvents involved, including recyclable chiral auxiliary, simplicity of the experimental procedures and high chemical yields, make this method synthetically attractive for preparing the target amino acids on a multi-gram scale. (C) 2000 Elsevier Science Ltd.